LGA 771 to 775 Adapter (MOD) – Run Cheap Xeon CPUs in a Core 2 Quad Motherboard

If you’re looking to extend the life of your LGA 775 system, there’s an adapter available now that will let you install cheap Intel Xeon processors (LGA 771) into an Intel Core 2 Quad motherboard (LGA 775). These Xeons cost a lot less and are basically identical internally to the high-end Core 2 Quad CPUs (and some of them are even faster).

Table of Contents

Why would you want to do this?

Xeons are usually MUCH cheaper

For example, the Xeon E5450 is equivalent to a 3.0 GHz Q9650 Core 2 Quad CPU, and it currently runs for about $45 on eBay (about $100 less than the Q9650).

Other good deals on LGA 771 Xeons include:

  • 3.33 GHz X5470 for $85
  • 3.16 GHz X5460 for $53
  • 3.00 GHz X5450 for $40
  • 2.83 GHz E5440 for $30
  • 2.50 GHz L5420 for $29

Xeons also typically overclock better

Additionally, if you’re interested in overclocking (making the cpu go faster than its default speed), Xeon processors are usually made from the best silicon (especially the lower voltage Xeons), so you can typically achieve higher overclocks with them.

Someone that recently did this mod successfully overclocked a Xeon X5470 from 3.33 GHz to 4.5 GHz on an ASUS P5Q PRO motherboard, so you can achieve really good results with these Xeons.

Where can I get an adapter?

The latest revision of this adapter is available here.

How does the adapter work?

The adapter is basically an electronic circuit on a sticker, and you place it on the Xeon processor (as shown in the picture below). This modifies some of the pins on the bottom of the Xeon to make it compatible with a Core 2 Quad motherboard.

Xeons that are compatible with this adapter

This adapter is only compatible with LGA 771 Xeon processors. If you’re unsure what LGA 771 means, it’s the name of the cpu socket used in some Xeon motherboards. And in comparison, LGA 775 is the name of the socket used in Core 2 Duo/Quad motherboards.

LGA 771 to 775 Adapter

Minor modification to the LGA 775 socket is also required

If you look at the LGA 775 socket in the picture below, you’ll notice two tabs are circled in red. These tabs are there to stop you from installing a non-LGA 775 processor, and they’ll need to be fully removed before you can install an LGA 771 cpu.

The tabs are pretty easy to remove if you have a sharp utility knife or box cutter (just be careful not to damage or bend any of the socket pins near the tabs).

Important: Make sure that you fully cut off each of these tabs. If they’re not fully cut off, the processor may not align or seat correctly in the socket, which will stop it from making contact with all of the pins. If this happens, your system will likely fail to boot.

Once the tabs are cut off, you can use tweezers to safely remove the pieces from the socket.

The socket will then support LGA 771 or 775 processors (you can still reinstall your old processor if you ever need to).

Tabs to removed from the LGA 775 socket

Motherboard Compatibility

Important - There are multiple versions of this adapter floating around. The latest revision seems to work best and can be found here.

Make sure you update your bios to the latest version before attempting this mod.

There are two requirements that your motherboard must meet in order to be able to run LGA 771 Xeon processors:

  1. You must have an LGA 775 motherboard with a compatible chipset.
  2. Your bios must support an LGA 775 CPU that’s similar to the Xeon you want to run.

We’ll explain how to verify these things in the sections below. And at the end, there’s also a list of motherboards that have been verified as compatible (and incompatible) with this mod.

First, make sure your motherboard’s chipset is compatible

The chipset we’re talking about here is technically called the North Bridge chipset. You can usually find what chipset your motherboard has by looking at its specification list.

Below you’ll find the list of chipsets that have been reported as compatible (and incompatible) with this mod.

If you have a motherboard with a chipset that isn’t in these lists, the mod will still likely work for you if your bios supports a similar LGA 775 processor. Just make sure your system isn’t mentioned in the list of incompatible chipsets and motherboards.

Chipsets that are compatible with all Xeons

Note: There are a few exceptions with some motherboards made by Intel themselves, so please read the rest of this section for more details.

  • P45, P43, P35, P31
  • G45, G43, G41, G35, G33, G31
  • nForce 780i, 750i, 630i
  • GeForce 9400, 9300
Some motherboards made by Intel don’t work with this mod

The pattern we’re noticing so far is that Intel brand motherboards that support Intel Viiv Technology don’t work with this mod (this is based on 3 failures so far). Intel Viiv Technology is supposed to help media center PCs function better. Additionally, the 3 Intel motherboards that have been reported to work with this mod do NOT support Intel Viiv Technology. However, we don’t have enough samples yet to know that Viiv is definitely the problem.

If your motherboard supports Intel Viiv Technology, you’ll usually see this mentioned in the specifications. Intel brand motherboards classified as Media Series usually support Viiv, but so do some of their other boards (like the DG33FBC), so you’ll need to check.

Chipsets that are ONLY compatible with 3xxx series Xeons (these are NOT compatible with the 5xxx series)

  • X48, X38
  • Q45, Q43, Q35, Q33

It’s been reported by many people that these chipsets do not support 5xxx series Xeons. By 5xxx series we mean any Xeon whose model number ends in 5xxx (this includes all the E5xxx, X5xxx, and L5xxx processors).

However, the 3xxx series (like the X3363) has been reported to work fine.

Our guess as to why some chipsets don’t support the 5xxx series Xeons (but do support the 3xxx series)

Xeons with model numbers that end in 5xxx are allowed to be used in motherboards that support 1 or 2 physical processors (this is called dual-processor support). However, the 3xxx series Xeons cannot be used in a multi-processor system (they’re labeled as supporting uni-processor configurations only).

There’s no noticeable difference between the E0 stepping E5440 and X3363 Xeons (other than one has dual-processor support), so it looks like this could be causing the problem.

* Please don’t confuse this with dual and quad core processors, which have multiple cores inside of 1 processor. We’re talking about multiple physical processors, which means you buy two separate processors and install them both in the same motherboard.

Chipsets with reported problems

If you have one of these chipsets, please click one of the links shown above for more details. If you don’t, you can move on to the next section: Next, make sure your BIOS supports a similar LGA 775 CPU.

Nvidia’s nForce 680i and 650i chipsets don’t officially support 45nm quad core processors

Some motherboards with these chipsets have worked with 45nm quad core Xeons, and some haven’t (please see the list of compatible motherboards for more details). This is likely due to some motherboards unofficially supporting 45nm quad core processors.

Because of this, we don’t recommend buying 45nm quad core Xeons if your motherboard has one of these chipsets (unless someone else with your motherboard has reported it worked). However, the 65nm Xeons are still an option and should work fine if your motherboard supports the Q6700.

Intel’s 3200/3210 chipset (used in server motherboards) doesn’t support 5xxx series Xeons

However, it’s possible this chipset will support the 3xxx series (nobody has tested this yet).

Next, make sure your BIOS supports a similar LGA 775 CPU

Note: Please read all of the headings in this section. There are important compatibility notes that are relevant for some motherboards and systems.

If your BIOS supports:You can run these Xeons:CoresTechnology
Q9650Harpertown (54xx) (with 1333 FSB)
Yorkfield-CL (33xx)
Q6700Clovertown (53xx) (with 1066 FSB)465nm
E8600Wolfdale-DP (52xx)
Wolfdale-CL (31xx)
E6850Woodcrest (51xx)265nm

Hopefully the table shown above is pretty self explanatory, but here’s an explanation if it isn’t. Each row shows an LGA 775 processor in the 1st column. If your bios supports that processor, you can run any of the LGA 771 Xeons shown in the 2nd column (of that same row).

For example, if your system supports the Q9650, you can run the Harpertown (with a 1333 FSB) and Yorkfield-CL Xeons. And, similarly, if it supports the Q6700, you can run any of the Clovertown Xeons (with a 1066 FSB).

For more details on the exact Xeon model numbers, please click the links in the table above.

Pay attention to the FSB of the Xeons

The Q9650 has a 1333 FSB, and the Q6700 has a 1066 FSB, so you should only get Xeons with those FSB speeds (or lower) — unless you’ve verified your motherboard supports higher FSB speeds. This is important because some of the Xeons have a higher FSB speed than the similar LGA 775 ones.

Make sure you only buy Xeons with a TDP supported by your motherboard

TDP is a measure of how much heat your processor’s cooling system will have to handle.

Some motherboards will not boot with processors over 95W (or 65W for low power boards).

TDPs for some common Xeon processors
  • L54xx series has a max TDP of 50W
  • E54xx series has a max TDP of 80W
  • X54xx series with a 1333 FSB has a max TDP of 120W
  • X54xx series with a 1600 FSB has a max TDP of 150W

A good way to check if your motherboard supports 120W and above processors is to check the CPU support list. If your system supports the 130W QX9650, you should be able to run the 120W X54xx series Xeons (and also probably the 150W Xeons with a 1600 FSB). However, if your system only supports the 95W Q6600 with a G0 stepping (and not the 105W B3 stepping), your system likely only supports 95W and below processors.

If you aren’t sure what TDP your motherboard supports, I’d recommend going with the 95W and lower Xeons only.

How to check what processors your motherboard supports

If you’re unsure if your bios supports one of these processors, please read the following article: How to Check if Your Motherboard Supports a Specific Processor.

Be careful if you have a prebuilt system (like a Dell)

If you have a prebuilt system (like a Dell), please read this warning concerning motherboard compatibility.

Note for low power (65W and below) systems

If you’re running a low power system (that only supports up to 65W) and your system supports the Q9550S, this mod should also work with the low wattage Xeons (like the L5420).

Motherboards that have been verified as working with this MOD

If you try this mod with a motherboard that isn’t in this list, please let us know by leaving a comment below (please also give us the Xeon model number and stepping if you know it).

MotherboardChipsetMax FSBMax TDPLGA 775 CPUs SupportedLGA 771 CPUs SupportedXeons tested
Abit AW9D-MAX975X / ICH7R1066At least 130WQ6700, QX6800All 65nm Xeons with a 1066 FSBL5320
Abit IP35 ProP35 / ICH9R1333At least 130WQ9550, QX9650Probably all (within FSB limits)E5420; Need bios update to support E0 stepping 45nm Xeons
Abit IP35-EP35 / ICH91333At least 130WQ9650, QX9650All (within FSB limits)E5440, E5420
ASRock G31M-SG31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, Q6600 (all steppings)All (within FSB and TDP limits)X5460, E5410
ASRock G31M-VS2G31 / ICH71333At least 130WQ9650All (within FSB and TDP limits)E5410
ASRock G41C-GSG41 / ICH71333At least 130WQ9650All (within FSB and TDP limits)X5460, X5450, X5260 (dual core)
ASRock G41M-VS3G41 / ICH71333At least 130WQ9650All (within FSB and TDP limits)X5450, E5205 (dual core), E5420
ASRock P43 Pro/USB3P43 / ICH101600At least 136WQ9650, QX9770AllL5430
ASRock P43D1600Twins-1394P43 / ICH101600At least 136WQ9650, QX9770AllE5430 (C0)
ASRock P43DEP43 / ICH101600At least 136WQ9650, QX9770All51XX, 52XX, 53XX, 54XX
ASRock P45TSP45 / ICH101600 or 2000 (when overclocked)At least 136WQ9650, QX9770AllE5430
ASRock P45x3P45 / ICH101600At least 136WQ9650, QX9770AllE5440
ASRock P5D-BEP965 / ICH81333At least 130WQ9650, QX9650All (within FSB limits)E5420 (E0)
ASUS P5G41T-M LXG41 / ICH71333At least 120WQ9650, Q6600 (95W only)All (within FSB and TDP limits)E5472, X5460, L5420, E5405
ASUS P5G41T-M LX PlusG41 / ICH71333At least 130WQ9650, QX9650All (within FSB limits)E5450, X5460 (SLBBA)
ASUS P5G41T-M SIG41 / ICH71333At least 136WProbably Q9650, QX9770Probably all (within FSB and TDP limits)E5420
ASUS Striker ExtremenForce 680i SLI (C55XE) / NVIDIA MCP55XE1333At least 130WQ6700, E860065nm quads (officially), but reported to also work with 45nm quadsX5460
ASUS Striker II ExtremenForce 780i SLI (C73XE rev. B1)1600At least 136WQ9650, QX9770AllE5472 (SLANR C0)
ASUS Striker II FormulanForce 780i SLI (C55XE)1333At least 136WQ9650, QX9770All (within FSB limits)X5470
ASUS P5BP965 / ICH81333 (with beta bios), 1066At least 130WQ9650, QX9650All (within FSB limits)E5450 (C0), E5440
ASUS P5B DeluxeP965 / ICH8R1333 (with beta bios), 1066At least 130WQ9650, QX9650All (within FSB limits)E5430
ASUS P5B-DEP965 / ICH81333At least 130WQ9650, QX9650All (within FSB limits)E5450
ASUS P5B-EP965 / ICH8R1333 (beta), 1066At least 130WQ9650, QX9650All (within FSB limits)E5450
ASUS P5B SEP965 / ICH81333 (beta), 1066At least 136WQ9650, QX9770All (within FSB limits)L5420 (C0)
ASUS P5KP35 / ICH91600At least 136WQ9650, QX9700AllE5440, E5450 (SLANQ), X5450, X5460 (SLBBA), x3363
ASUS P5K DeluxeP35 / ICH9R1600At least 136WQ9650, QX9700AllL5420
ASUS P5K ProP35 / ICH9R1600At least 136WQ9650, QX9700AllE5440 (C0)
ASUS P5K SEP35 / ICH91600At least 136WQ9650, QX9770AllX3363
ASUS P5K-EP35 / ICH9R1600At least 136WQ9650, QX9770AllE5440, X5450
ASUS P5KCP35 / ICH91600At least 136WQ9650, QX9770AllE5450
ASUS P5KLP SEG31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770All (within FSB limits)L5410
ASUS P5KPL/1600G31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770All (within FSB limits)L5420
ASUS P5KPL AM/PS (rev. 2.01G)G31 / ICH71333 or 1600 (when overclocked)150WQ9650, QX9770All (within FSB limits)X5482
ASUS P5KPL-AMG31 / ICH71333 (or 1600 when overclocked)At least 136WQ9650, QX9770All (within FSB)X5460 (SLANP), X5450 (E0), L5420
ASUS P5KPL-AM EPU (rev. 1.01G)G31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770All (within FSB)X5450 (E0), L5420
ASUS P5KPL-CMG31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770All (within FSB)X3323
ASUS P5KRP35 / ICH9R1600At least 136WQ9650, QX9770AllL5420
ASUS P5P43TD (rev. 1.00G)P43 / ICH101333 or 1600 (when overclocked)At least 130WQ9650, QX9650All (within FSB limits)E5450, X5450
ASUS P5P43TD PRO (rev. 1.02G)P43 / ICH10R1333 or 1600 (when overclocked)At least 136WQ9650, QX9770All (within FSB limits)X5460
ASUS P5N-DnForce 750i SLI (C72P) / nForce 430 (MCP51)1333At least 130WQ9650, QX9650All (within FSB limits)E5450
ASUS P5N-EM HDMInForce 630i1333At least 130WQ9650, QX9650All (within FSB limits)X5260
ASUS P5N-T Deluxe (rev. 1.02G)nForce 780i SLI / nForce 570 SLI1333At least 136WQ9650, QX9770All (within FSB limits)E5450
ASUS Maximus II FormulaP45 / ICH10R1600At least 136WQ9650, QX9770AllE5450, X5460, X5470
ASUS P5QP45 / ICH10R1600At least 136WQ9650, QX9770AllE5450, L5430
ASUS P5Q ProP45 / ICH10R1600At least 136WQ9650, QX9770AllE5450, E5462, X5460, E5440
ASUS P5Q Pro TurboP45 / ICH10R1600At least 136WQ9650, QX9770AllX5470, E5450
ASUS P5Q DeluxeP45 / ICH10R1600At least 136WQ9650, QX9770AllX5470, X5450, X5460 (E0)
ASUS P5Q PremiumP45 / ICH10R1600At least 136WQ9650, QX9770AllX5470
ASUS P5Q SE/RP45 / ICH10R1600At least 136WQ9650, QX9770AllE5450
ASUS P5Q SE2P45 / ICH101600At least 136WQ9650, QX9770AllE5420 (SLBBL)
ASUS P5Q SE PLUSP45 / ICH101600At least 136WQ9650, QX9770AllE5450 (C0 stepping)
ASUS P5Q3 (revision 1.00G)P45 / ICH10R1600At least 136WQ9650, QX9770AllE5450, L5430, L5420
ASUS P5Q3 DeluxeP45 / ICH10R1600150WQ9650, QX9770AllE5450 (C0), E5440 (C0), X5450 (E0 & C0), E5420 (E0), E5462, X5482 (E0)
ASUS P5QL-EP43 / ICH10R1333 or 1600 (when overclocked)At least 136WQ9650, QX9770All (within FSB limits)E5450, L5420
ASUS P5QL PROP43 / ICH101333 or 1600 (when overclocked)At least 136WQ9650, QX9770All (within FSB limits)E5410, E5450, x3353
ASUS P5QL-VM EPU (rev. 1.01G)G43 / ICH101333At least 130WQ9650, QX9650All (within FSB limits)X5460
ASUS P5Q-EP45 / ICH10R1600At least 136WQ9650, QX9770AllE5450, X5460, L5430
ASUS P5Q-EMG45 / ICH10R1600At least 136WQ9650, QX9770AllX5470, X5460 (SLBBA), E5450
Biostar G41 DVIG41 / ICH7133395WQ9550 (C1 stepping), Q6600 (95w only)All (within FSB and TDP limits)E5450
Biostar TPower i45 (ver 5.x)P45 / ICH10R1333 or 1600 (when overclocked)At least 136WQ9550 (E0 stepping), QX9770All (within FSB limits)X5450
Biostar TP43E XE (ver 5.x)P43 / ICH101333 or 1600 (when overclocked)At least 136WQ9550 (E0 stepping), QX9770All (within FSB limits)E5472, L5420
Biostar P43D2-A7P43 / ICH101333 (not sure about 1600)At least 105WProbably Q9650All (within FSB and TDP limits)E5450
Biostar TP43D2-A7P43 / ICH101333 (or 1600 with overclock)At least 105WQ9550 (SLAWQ)Probably all (within FSB and TDP limits)E5440
DFI P45-T2RSP45 / ICH10R1333At least 130WQ9650, QX9650All (within FSB limits)X5460
DFI LANPARTY JR GF9400-T2RSGeForce 94001333At least 130WQ9650, QX9650All (within FSB limits)X5460
Dell Precision T3400X38at least 1333At least 130WQ9650, QX9650All 3xxx series Xeons (within FSB and TDP limits). The 5xxx series is incompatible.X3363
Dell Optiplex 330G31 / ICH7Rat least 1333At least 95WQ6700; Q9550 (C0 stepping)Doesn’t fully support E0 stepping Xeon processors, so you may run into issues with those, but the C0 stepping Xeons have been reported to work fine.E5450 (C0 stepping), E5440 (C0 stepping), 5160
Dell Optiplex 360G31 / ICH7at least 1333At least 95WQ9550 (C0 stepping)Doesn’t fully support E0 stepping Xeon processors, so you may run into issues with those, but the C0 stepping Xeons have been reported to work fine.E5440 (C0 stepping)
Dell Optiplex 755 (all form factors)Q35 / ICH9DOat least 1333At least 95WQ9650All 3xxx series Xeons (within FSB and TDP limits). The 5xxx series is incompatible.X3363, X3323
Dell Vostro 200 (with G33M02 motherboard)G33At least 1333At least 80WDual core onlyAt least 65nm dual core5160
Dell Vostro 400 (with G33M03 motherboard)G33 / ICH91333At least 120WQ9650All (within FSB and TDP limits)X5470
eMachines EL1830nForce 630iat least 1066At least 50W??L5320
EVGA NF66nForce 650i Ultra1333At least 95WQ9650All (within FSB and TDP limits)E5450
EVGA nForce 680i SLI (122-CK-NF68)nForce 680i1333At least 120WProbably Q9650Probably all (within FSB and TDP limits)X5450, E5420
EVGA 750i FTWnForce 750i SLI / nForce 4301333At least 136WQ9650, QX9770All (within FSB limits)X5460
EVGA nForce 780i SLInForce 780i1333At least 136WQ9650, QX9770All (within FSB limits)X5460, X5470
EVGA 790i FTWnForce 790i SLI1600At least 130WQ9650, QX9650All
Foxconn G31MG31 / ICH71333 (or 1600 when overclocked)At least 105WQ9650, Q6700, Q6600 (all steppings)All (within FSB and TDP limits)E5450 (SLANQ)
Foxconn G31MXPG31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650All (within FSB limits)
Foxconn G41MXEG41 / ICH7133395WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)E5450 (SLBBM)
Foxconn G41MXF 2.0G41 / ICH71333At least 95WQ9650All (within FSB and TDP limits)E5420
Foxconn MCP73S01GeForce 7100 / nForce 630i1333At least 120Wprobably Q9650Probably all (within FSB and TDP limits)X5460 (E0)
Foxconn P35AX-SP35 / ICH91333At least 130WQ9650, QX9650All (within FSB limits)E5405
Fujitsu D2841-A1G41At least 1333At least 80WProbably Q9650Probably all (within FSB and TDP limits)E5405
Fujitsu Esprimo E3521G41At least 1333At least 80WQ9550Probably all (within FSB and TDP limits)E5450
Gigabyte EG41MF-US2HG41 / ICH71333At least 135Wq9650, QX9770All (within FSB limits)E5450, L5430
Gigabyte EP31-DS3LP31 / ICH71333 or 1600 (when overclocked)At least 135Wq9650, QX9770All (within FSB limits)E5450
Gigabyte EP35-DS3LP35 / ICH91333 or 1600 (when overclocked)At least 135Wq9650, QX9770 (with overclock)All (within FSB limits)E5450
Gigabyte EP35C-DS3RP35 / ICH9R1333 (or 1600 when overclocked)At least 136Wq9650, QX9770 (with overclock)All (within FSB limits)E5450
Gigabyte EP41T-USB3G41 / ICH71333At least 130WQ9650, QX9650All (within FSB limits)X5450
Gigabyte EP43-DS3P43 / ICH101333 or 1600 (when overclocked)At least 135WQ9650, QX9770All (within FSB limits)E5440, E5430
Gigabyte EP43-DS3LP43 / ICH101333 or 1600 (when overclocked)At least 135WQ9650, QX9770All (within FSB limits)L5420
Gigabyte EP43-UD3LP43 / ICH101333 or 1600 (when overclocked)At least 135WQ9650, QX9770All (within FSB limits)X5460
Gigabyte EP43T-S3LP43 / ICH101333 or 1600 (when overclocked)At least 135WQ9650, QX9770All (within FSB limits)E5450
Gigabyte EP45-DS3P45 / ICH101600At least 135WQ9650, QX9770AllX5470
Gigabyte EP45-DS4P45 / ICH10R1600At least 135WQ9650, QX9770AllE5472
Gigabyte EP45-UD3LP45 / ICH101600At least 135WQ9650, QX9770AllX5460
Gigabyte EP45-UD3PP45 / ICH10R1600At least 135WQ9650, QX9770AllX5470, X5460 (E0), E5450, E5440, L5240
Gigabyte EP45-UD3RP45 / ICH10R1600150WQ9650, QX9770AllX5460, X5492, L5420
Gigabyte EP45C-DS3P45 / ICH101600At least 135WQ9650, QX9770AllE5450
Gigabyte EP45C-DS3RP45 / ICH10R1600At least 135WQ9650, QX9770AllE5450, L5430
Gigabyte EP45C-UD3RP45 / ICH10R1600150WQ9650, QX9770AllX5492 (overclocked to 4 GHz)
Gigabyte EP45T-DS3RP45 / ICH10R1600At least 135WQ9650, QX9770AllE5450, X5460
Gigabyte EP45T-UD3RP45 / ICH10R1600At least 135WQ9650, QX9770AllE5450
Gigabyte EP45T-UD3LRP45 / ICH10R1600At least 135WQ9650, QX9770AllX5492, E5430, X5460, L5430
Gigabyte EP45T-USB3PP45 / ICH10R1600At least 136WQ9650, QX9770AllX5470, X5460
Gigabyte EX38-DQ6X38 / ICH9R1600At least 135WQ9650, QX9770All 3xxx series Xeons (the 5xxx series is incompatible)X3363
Gigabyte G31M-ES2LG31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, QX9650All (within FSB limits)X5460 (E0)
Gigabyte G31M-S2LG31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, QX9650All (within FSB limits)X5460, E5335, E5405, L5430
Gigabyte G41MT-D3G41 / ICH71333At least 95WQ9650, Q6700, Q6600 (95W only)All (within FSB and TDP limits)L5430
Gigabyte G41MT-ES2LG41 / ICH71333At least 95WQ9650, Q6700, Q6600 (95W only)All (within FSB and TDP limits)X3353
Gigabyte G41MT-S2P (rev 1.3)G41 / ICH71333At least 95WQ9650All (within FSB and TDP limits)E5430
Gigabyte G41M-ES2HG41 / ICH71333At least 95WQ9650All (within FSB and TDP limits)E5420
Gigabyte G41M-ES2LG41 / ICH71333At least 95WQ9650, Q6700, Q6600 (95W only)All (within FSB and TDP limits)E5450
Gigabyte P31-DS3LP31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, QX9650All (within FSB limits)X5260 (3.33 ghz dual core)
Gigabyte P31-ES3GP31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, QX9650All (within FSB limits)E5450
Gigabyte P35-S3GP35 / ICH91333At least 135WQ9650, QX9770All (within FSB limits)E5410
Gigabyte P35-DS3LP35 / ICH91333 or 1600 (when overclocked)At least 135WQ9650, QX9770All (within FSB limits)E5440, L5410
Gigabyte P35-DS3RP35 / ICH9R1333At least 135WQ9650, QX9770All (within FSB limits)E5420, E5405 (2ghz quad)
Gigabyte P35C-DS3RP35 / ICH9R1333 or 1600 (when overclocked)At least 130WQ9650, QX9650All (within FSB limits)E5440, L5240
Gigabyte P35-DQ6P35 / ICH9R1333 or 1600 (when overclocked)At least 130WQ9650, QX9650All (within FSB limits)E5450 (C0)
Gigabyte P41-ES3GG41 / ICH7133395WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)X5260 (3.33 ghz dual core)
Gigabyte P43-ES3GP43 / ICH101333 or 1600 (when overclocked)At least 135Wq9650, QX9770All (within FSB limits)e5430
Gigabyte X38T-DQ6X38 / ICH9R1600At least 135WQ9650, QX9770All 3xxx series Xeons (the 5xxx series is incompatible)X3363
Gigabyte 965P-S3 (rev 3.3)P965 / ICH81333At least 130WQ9650 (unofficial), QX9650 (unofficial)65nm quads (officially), but probably also 45nm quads (unofficially)E5440 (C0), X5260 (3.33 ghz dual core)
Gigabyte 965P-DS3 rev 3.3P965 / ICH81333At least 130WQ9650 (unofficial), QX9650 (unofficial)All (within FSB limits)E5450, X5460, X5260
Gigabyte 965P-DS3P (rev 3.3)P965 / ICH8R1333At least 130WQ9650 (unofficial), QX9650 (unofficial)All (within FSB limits)E5420
HP DX2400G33 / ICH9RAt least 1333At least 95WQ9650All (within FSB and TDP limits)X5450
HP IPIBL-LB (Benicia)G33 / ICH91333At least 95Wprobably Q9650All (within FSB and TDP limits)L5420
Intel DG31PRG31 / ICH7at least 133395WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)E5450
Intel DG33M04G33 / ICH91333At least 95WQ9650, Q6700All (within FSB and TDP limits)E5450
Intel DG41MJG41 / ICH7At least 133365WQ9550SAll (within FSB and TDP limits)L5430
Intel DG41RQ (depends on revision)G41 / ICH7at least 133395WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)x3353
Intel DP43TFP43 / ICH10133395WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)E5450 (C0)
Intel DP45SGP45 / ICH10R1600At least 130WQ9650, QX9650AllE5440 (E0)
J & W JW-P45D2-UltraP45 / ICH10R1600At least 95WProbably Q9650Probably all (within FSB and TDP limits)E5410 (c0 stepping)
Jetway Xblue-P43-LP43 / ICH101600At least 95W (probably 135W)Q9650, QX9770 (out of spec), Q6700 (no Q6600 listed)All (within FSB and TDP limits)L5420, E5205, E5110
MSI G31M3-L V2G31 / ICH7133395WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)E5430, E3113 (dual core), E5205 (dual core)
MSI G41M-P23G41 / ICH7133395WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)E5450
MSI G41M-P25G41 / ICH71333At least 95WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)E5450
MSI G41M-P33 ComboG41 / ICH7133395WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)E5450
MSI P35 NEO2-FRP35 / ICH9R1600At least 136WQ9650, QX9770AllE5420
MSI P35 PlatinumP35 / ICH9R1600At least 136WQ9650, QX9770AllE5450, X5460, X5450, L5420
MSI P43-C51P43 / ICH101333 or 1600 (when overclocked)At least 136WQ9650, QX9770All (within FSB limits)E5420, L5420
MSI P45D3 Neo-FP45 / ICH101600At least 135WQ9650, QX9770AllE5462
MSI P45 Neo-FP45 / ICH101600At least 135WQ9650, QX9770AllE5450 (SLBBM)
MSI P45 Neo2P45 / ICH10R1600At least 135WQ9650, QX9770AllE5450 (C0)
MSI P45 PlatinumP45 / ICH10R1600At least 135WQ9650, QX9770AllE5450, X5460
MSI P6N SLI PlatinumnForce 650i SLI1333At least 105WQ6700, Q6600 (all steppings)All 65nm quad core (within FSB and TDP limits); 45nm quads are not supported.E5345 (SLAEJ)
Pegatron IPMEL-PRCG41 / ICH7133395WProbably Q9650Probably all (within FSB and TDP limits)E5405
Shuttle SG33G5G33 / ICH9DH1333At least 95WQ9650Probably all (within FSB and TDP limits)
XFX 680i ltnForce 680i LT SLI1333At least 130WQ6700, QX685065nm quads (officially), but reported to also work with 45nm quadsE5450, X5460
XFX 780inForce 780i1333At least 120WProbably Q9650, probably QX9650Probably all (within FSB and TDP limits)X5460
XFX 790inForce 790i Ultra1600At least 136WQ9650, QX9770AllX5470 (E0), E5440
XFX 9300GeForce 9300133395WQ9650, Q6600 (95W only)All (within FSB and TDP limits)L5420
Zotac 620i (MCP73)nForce 620i1333At least 120WQ9650All (within FSB and TDP limits)X5460
Zotac GF9300 ITXGeForce 9300133395WQ9650, Q6700, Q6600 (G0 only)All (within FSB and TDP limits)E5440

Motherboards that should be compatible (but haven’t been tested yet)

MotherboardChipsetMax FSBMax TDPLGA 775 CPUs SupportedLGA 771 CPUs Supported
Acer Aspire G7700nForce 780i1333At least 130WQ9650, QX9650All (within FSB limits)
AsRock P43Twins1600P43 / ICH101600At least 136WQ9650, QX9770All
ASUS P5E-VM HDMIG35 / ICH9RAt least 1333At least 130WQ9650, QX9650All (within FSB limits)
ASUS P5G41C-M LXG41 / ICH7At least 1333At least 95WQ9650, Q6600 (95W only)All (within FSB and TDP limits)
ASUS P5K3 Deluxe/WiFi-APP35 / ICH9R1600At least 136WQ9650, QX9770All
ASUS P5KPL SEG31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770All (within FSB)
ASUS P5NE-SLInForce 650i1333At least 105WQ6700, Q6600; 45nm quads are not supportedAll 65nm Xeons (within FSB and TDP limits)
ASUS P5Q-SE2 (rev. 1.00G)P45 / ICH101600At least 136WQ9650, Q6700, Q6600, QX9770All
ECS G41T-M12G41 / ICH71333At least 95WQ9650 (no Q6600 support)All (within FSB and TDP limits)
Foxconn G41S-KG41 / ICH7133365WQ9550SAll (within FSB and TDP limits)
Gigabyte 965P-DQ6P965 / ICH8R1333At least 136WQ9650 (non official), QX9650 (non official)Probably all
Gigabyte EP43-S3LP43 / ICH101333 (or 1600 when overclocked)At least 136WQ9650, QX9770All
Gigabyte EP45-UD3LRP45 / ICH10R1600At least 136WQ9650, QX9770All
Intel DG41MJG41 / ICH7At least 133365WQ9550SAll 65W and lower Xeons
MSI G31M (MS-7379 version 2)G31 / ICH71333At least 130WQ9650, QX9650All (within FSB and TDP limits)

Motherboards that are incompatible with at least some Xeons

Most of these motherboards seem to be incompatible with 5xxx series Xeons. However, most of these should be compatible with the 3xxx series.

MotherboardChipsetMax FSBLGA 775 CPUs SupportedCompatible with 5xxx series XeonsXeons testedTimes reportedNotes
Acer Q35T-AMQ35 / ICH9DO1333Q9650NoE54501
ASUSX48 and X38NoMultiple
ASUS Maximus FormulaX38No1
ASUS Rampage FormulaX48 / ICH9R1600Q9650, QX9770NoX52601
ASUS P5EX38 / ICH9R1600Q9650NoE5310Multiple
Clevo D901CP965 / ICH8Rat least 1333Q9650NoE54501Did work with an X3363. I think this is a special desktop/laptop hybrid, so it’s definitely not a typical system.
Compaq dc7900Q45Q9650NoE5450, X54502
Compaq DC5800Q33at least 1333Q9650No?1
Dell Optiplex 755Q35 / ICH9DOat least 1333Q9650NoE54403
Dell Optiplex 760Q43 / ICH10DNo
Dell Optiplex 960Q45 / ICH10DOat least 1333Q9650NoE5450Multiple
DFIX48 and X38No
DFI X48-T3RSX48E5430
Gigabyte EX38-DS4 (rev. 1.1)X38 / ICH9R1600Q9650, QX9770NoE54401Tried multiple CPUs, stickers, and updated microcode.
Gigabyte EX38-DQ6X38 / ICH9R1600Q9650, QX9770NoE54401The 5xxx series is incompatible, but the 3xxx series has been verified to work.
Intel DG33FBC (supports Intel Viiv Technology)G33 / ICH9DHNoE5450, Two X54602With the X5460, the Xeons and adapter worked in another motherboard.
Intel DG33TL (supports Intel Viiv Technology)G33 / ICH9RNoX5450, E54501Same person tried both Xeons.
Intel DP35DP (supports Intel Viiv Technology)P35 / ICH9RNoE54501
Intel DQ35JOEQ351333Q9650NoE5450, X54501
Intel DX48BT2X48No51501Also tried bios mod.
Intel S3200SH (server motherboard)Intel 3200/3210 / ICH9R1333X3370 (E0 stepping), QX9650, Q9550 (C1), Q6600NoE54401
Lenovo M58 SFFQ45 / ICH10DO1333Q9650NoE54401
Supermicro C2SBX+X48 / ICH9R1600Q9650, QX9770NoX54921

Important: Make sure you only buy Xeon processors with a FSB and TDP supported by your motherboard.

The best deals on LGA 771 Xeons are shown in the tables below.

Cheap 45nm Harpertown Xeons

These are compatible with systems that support the Q9650.

ModelFrequencyCoresL2 CacheFSBMultiplierTDPeBay Price
X54703.33 GHz42 x 6 MB133310120 W$89
X54603.16 GHz42 x 6 MB13339.5120 W$53
E54503.0 GHz42 x 6 MB1333980 W$40
X54503.0 GHz42 x 6 MB13339120 W$40
E54402.83 GHz42 x 6 MB13338.580 W$33
L54202.5 GHz42 x 6 MB13337.550 W$32

Cheap 65nm Clovertown Xeons

These are compatible with systems that support the Q6700. However, to run a Xeon with a 1333 FSB, your motherboard must support that FSB speed.

ModelFrequencyCoresL2 CacheFSBMultiplierTDPeBay Price
X53653.0 GHz42 x 4 MB13339150 or 120 W$98 (price has gone up)
X53552.67 GHz42 x 4 MB13338120 W$24

I only listed the Xeon processors that are decently fast (over 2.4 GHz) and are relatively cheap right now. For a full list of all the compatible Xeon processors, please see the Xeon CPU list from the previous section.

And although I didn’t list them here, you may also be able to find some good deals on the 1600 FSB Xeons. Just make sure your motherboard supports that FSB before buying them.

Detailed instructions for completing this mod

Disclaimer: Please attempt this mod at your own risk. We are not responsible for any damage you do to your system while performing this mod.

Things you’ll need

Step 1 – Install the latest BIOS and verify it’s compatible with your Xeon cpu

BIOS updates often add support for new processors, so you have the best chance of this working with the latest bios for your motherboard.

If you haven’t done this already, you should also verify that your bios is compatible with the Xeon processor you want to install. If it isn’t, your system will likely fail to boot.

Step 2 – Reset your BIOS

Before you get started with the mod, it’s recommended that you reset your bios. This will avoid many potential problems you may run into.

With your system turned off and power cord unplugged, reset your BIOS through the jumper on your motherboard or by removing the CMOS battery.

If you’re unsure how to do this, take a look at the following page: How to reset your bios.

Step 3 – Modify the LGA 775 socket to support LGA 771 CPUs

This step was already explained earlier on this page.

Step 4 – Attach the adapter to the Xeon processor

First, wash your hands thoroughly and dry with a paper towel

This is necessary in case your fingers come in contact with the adhesive of the adapter. Clean hands are less likely to weaken the adhesive.

Make sure the top-right edge of your adapter is only 1 pad long

If you look at the adapter shown below, you’ll notice the top-right edge of the adapter (with the letter T) is only 1 pad long horizontally and doesn’t cover any of the pads to the right of it. This is how your adapter should look when you attach it to your Xeon processor (some adapters may have something else in the top-right corner instead of the letter T).

If the top-right edge of your adapter is longer than the width of 1 pad, you’ll need to cut it to look like the picture below.

If you bought your adapter from here, it should come precut the correct length (but you should still double check).

LGA 771 to 775 Adapter

LGA 771 to 775 Adapter

Remove the cover from the adhesive

The latest revision of this adapter comes with adhesive preapplied to the bottom of both ends of the adapter, which will help it stick to the processor. If yours does, peel off the protective cover to reveal the adhesive.

Safest way to remove the adhesive covers

The easiest way to safely remove the adhesive cover is to hold the adapter right below the cover that you want to remove. You then peel upward (toward the top of the adapter) like you’re trying to peel off a sticker.

Just be careful to not damage the 2 metal pads in the center of the adapter or overly bend the adapter when removing the covers.

If your adapter doesn’t come with adhesive or it isn’t sticking very well

You can also use double-sided tape to secure it to the CPU. Just apply the tape to both ends and cut off any excess. Make sure the tape won’t cover any of the pads on the processor.

Line up the adapter on the bottom of the Xeon cpu

Static electricity warning: The circuits on the processor (above where the adapter goes) are sensitive to static electricity, so touch a screw on the back of your computer to discharge yourself before handling it. If you’re using metal tweezers, it would also be a good idea to discharge them as well.

Carefully lay the adapter onto the processor and align it as shown in the previous picture. Tweezers are helpful here.

Make sure the triangle on the bottom of the adapter is pointing toward the triangle on the CPU (some adapters have an arrow in the bottom-right-hand corner instead of a triangle).

Important: Take your time and make sure the adapter is aligned exactly as shown in the picture (you may want to use a magnifying glass to verify). If it’s off by much or covering some pads that it shouldn’t, your system may fail to boot.

When you’re confident the adapter is lined up correctly, press down on both ends to secure it to the processor.

Now double check that the adapter is still lined up correctly and is tightly connected to the processor. You don’t want the adapter moving when you install it into the socket.

Step 5 – Install the CPU into the socket

Make sure the triangle on the processor is lined up with the triangle in the socket as shown in the picture below.

Important: Ensure that the processor is fully seated in the socket before closing the lid (try wiggling the CPU a little). If the plastic tabs were not cut off fully, it may not make contact with all of the pins in the socket. This is a common installation error, and if this happens, your system will likely fail to boot.

Place the cpu in the socket

Place the cpu in the socket

Step 6 – Finishing up

When you start the system for the first time, we recommend that you go into the BIOS and load the default settings.

Your system may cut itself on and off several times before booting up correctly. This is normal with some systems, and it should start normally in the future.

If you run into any problems, please read the troubleshooting section on this page. It covers most of the common things that can go wrong during installation.

And as mentioned earlier, if you don’t have an adapter yet, you can get the latest revision from here.

Please let us know if this mod worked on your system

If you tried this mod on your system, please leave a comment below with your:

  • Motherboard model number (and revision if it has one)
  • Xeon model number (and stepping if you know it)

And we’ll add this information to the motherboard compatibility section, which will help other people that are also using your motherboard.

Troubleshooting Problems

I’m getting a message during bootup telling me to update my bios

You may get a message during startup with some motherboards (usually ASUS) telling you to update your BIOS. This happens because your motherboard doesn’t contain the exact Xeon microcode for your processor, and it’s using the similar LGA 775 microcode instead.

This typically isn’t a problem (except for the annoying message), and your system will normally function fine. You can usually stop this message from slowing down your bootup by disabling Halt boot on error in the bios. However, you can also add the LGA 771 microcode to your bios to stop this message from appearing.

If you are experiencing any other problems besides the error message, please take a look at this topic.

My system will POST (you can enter the BIOS), but Windows won’t load

The first thing you should try is loading the default settings in the bios. This has worked for most people.

If that doesn’t help, this problem is also sometimes due to the SATA hard drive mode getting reset when you reset your BIOS to its default settings. If this setting is different than what is was when you installed Windows, Windows will likely fail to load. The options are usually AHCI, IDE (sometimes listed as ATA), and RAID.

If this doesn’t help, please try what’s suggested in: My system will boot up, but my Xeon is not working as expected. It’s also relevant to this problem.

My system will boot up, but my Xeon is not working as expected

Try resetting your bios

If your system boots up fine, but it’s not working as expected, the first thing you should try is to reset your bios to its default settings.

Try removing the CMOS battery

If resetting the bios doesn’t help, you can try unplugging the power cable from the back of the computer, taking out the CMOS battery from the motherboard, and waiting 30 seconds before putting it back in. This should fully reset your bios and any of the information it’s stored about your old processor.

Once your system boots up, make sure you go into the bios and load the default settings.

Try adding the LGA 771 microcode to your bios

If pulling the CMOS battery doesn’t help, then you should try a bios mod. A bios mod will add the exact LGA 771 Xeon microcode to your bios (instead of using the similar LGA 775 microcode), and this should fix most problems.

How to add the LGA 771 microcode to your bios

If you have an Award or AMI bios, you can add the LGA 771 Xeon microcode yourself by following these directions. I’ve heard Phoenix BIOSes can also be modified the same way as an Award, but I haven’t tested this.

If you have a different type of bios, you can also request a bios mod at that same page or at bios-mods.com.

Just tell them:

  • Your motherboard model number (and revision if it has one)
  • The type of bios you have (Award, AMI, Phoenix, etc..)
  • A link to your most recent bios
  • The model number and stepping for your Xeon
  • And the model number for your old LGA 775 processor (so they can make sure they leave the microcode for that processor)

Try reinstalling Windows

And, lastly, if a bios mod doesn’t help, you should try reinstalling windows. This has helped for multiple people that were having problems like rebooting, BSOD, or other lockups.

I’m just getting a blank screen when I turn on my computer

Make sure your motherboard is compatible with your Xeon

If your motherboard has an incompatible chipset, your bios doesn’t support an LGA 775 processor that’s similar to your Xeon, or your Xeon’s TDP is higher than your motherboard will allow, your system will likely fail to boot up correctly. This is explained in the motherboard compatibility section earlier on this page.

However, you may still be able to get the system to boot up by doing a bios mod. Please see the previous link for details.

Try resetting your BIOS to its default settings

Resetting your BIOS will fix many problems, so it’s usually the first thing you should try.

Check for the following common installation problems, and try the installation again

Below you’ll find common problems that can happen during installation.

  • Make sure the 2 plastic tabs are fully cut off and removed from the socket.  If they aren’t, the Xeon may not seat correctly in the socket, which is mentioned next.
  • Make sure the processor is fully seated in the socket (try wiggling it slightly). This is a common problem that often happens if the plastic tabs in the socket are not cut off fully (but it could still happen even if they are). If the processor isn’t seated correctly, it will not be able to make contact with all of the pins in the socket, and the system will likely fail to boot.
  • Adapter not lined up correctly on the bottom of the Xeon. If the placement is off by even a little or covers something it shouldn’t, you’ll likely run into problems. Use a magnifying glass to verify the adapter is aligned correctly.
  • Adapter is not tightly attached to the processor. If the adhesive is weakened, the adapter may move when installed in the socket, which can cause problems. Try pushing on the top and bottom of the adapter a little to make sure it doesn’t move.
  • Top-right edge of the adapter is too long and covers some of the pads on the processor. If this happens, you’ll need to cut the top-right edge to make it shorter.
  • A pin in the socket is bent. It’s possible some of the pins got bent when you were removing the two plastic tabs from the socket. If you notice bent pins, we recommend that you try to straighten them using tweezers and a magnifying glass (a small knife may also help).

Even if none of these seem like the problem, I still recommend rereading the installation instructions carefully and trying the installation again. You may notice something or fix some issue that you missed the first time.

Try adding the LGA 771 Xeon microcode to your BIOS

Most motherboards should work fine if your bios supports one of the similar LGA 775 CPUs mentioned in the motherboard compatibility section. However, it is possible your motherboard may need the exact LGA 771 Xeon microcode in order to function properly. This microcode can be added with a bios mod. You can find more details on obtaining a bios mod for your motherboard at the previous link.

Try reinstalling your old LGA 775 cpu

If you’re still having problems, you should reinstall your old LGA 775 cpu to make sure your system is still working correctly.

If your system still works with your old processor, you at least know nothing on your motherboard was damaged during the mod.

However, if your old processor won’t even work, please read this.

If you’re still having problems

If you’re still having problems after trying the above fixes (including the bios mod), you can try the following as a last resort.

Try another adapter

The adapter may be defective, so I recommend contacting the seller for a replacement.

If that doesn’t work, try another Xeon processor

If you’re still having problems with the replacement adapter, your Xeon CPU may be defective, so I recommend returning it for another.

My old processor no longer works

The most common cause of the old processor no longer working is bent socket pins. It’s possible some of the pins got bent when you were removing the two plastic tabs from the socket. If you notice bent pins, we recommend that you try to straighten them using tweezers and a magnifying glass (a small knife may also help).

If bent pins aren’t the issue, make sure the socket doesn’t have any stray pieces of plastic (from when you removed the tabs). It’s possible this could be stopping the processor from seating correctly in the socket.

If neither of these help, we recommend that you try to install your old processor again. It’s possible it wasn’t making a connection with all of the socket pins. Wiggling the processor when it’s in the socket can sometimes help.


  1. How would I know this sticker circuit wont just melt down or burn out after a couple of months? How good is the quality of this circuit?

    • People have been doing this mod since around March of this year, and I haven’t heard of any problems with adapters failing months down the road.

      Since the adapter is applied to the bottom of the cpu, it isn’t subjected to the high temperatures found on the top of the cpu, so heat also shouldn’t be an issue.

      I’ve had a Xeon running overclocked (which means even more heat and voltage than normal) for months, and it still runs great.

  2. I currently have an ASUS P5N-D

    It supports the Core 2 Quad Q9650(rev.E0,3.00GHz,1333FSB,L2:12MB) and the Core 2 Quad Q6700 (2.66GHz,1066FSB,L2:2X4MB,rev.G0,4 cores). In theory the mod should work. The question is, how hard is it to actually cut off those plastic parts on the motherboard? Is it really that easy now? I am just concerned, because this all sounds convincing but the actual work of having tu cut off plastic near those socket pins seems kind of risky…

    • The plastic tabs come off pretty easily as long as you have a sharp utility knife. The only time I had a hard time was when I was using an old rusted box cutter that was dull.

      You do have to be careful around the socket pins, but if you are, it should go fine. I haven’t heard of anyone bending any pins.

      • I’ll give this a shot, but I may have trouble with the BIOS. The thing is I don’t know what BIOS I have because I have never put any CPU on this board. I may have to buy a very cheap processor just for the BIOS update…
        I got the Intel Xeon X5450 3.0 GHz, which has a TDP of 120W. I am not sure what that means, but I sure hope it doesnt mean I’m having major heat issues. I do not plan to overclock. Would a regular and cheap fan/heat sink suffice?

        • TDP is a measure if how much power the cooling system will need to dissipate.

          With the X5450, you’re supposed to buy a heatsink and fan that’s rated for 120W or above. Now, realistically, I’m not sure if you’d run into problems with a regular cheap fan/heatsink if you aren’t overclocking or running stress tests or something, but I’ve never tried it, so you’d be taking a risk.

          The E5450 is probably better if you’re wanting to run with a cheap heatsink/fan, since it’s rated at 80W.

          • Hmm, yes I don’t know how this stuff works, but it would suck if the CPU pulls 120 Watts and that somehow burns out the Motherboard since its not a server-grade motherboard, but perhaps I could download some sort of CPU wattage/temperature monitoring software, and if stuff is looking bad then perhaps I could under-clock the CPU. I’ll wait and see what happens. I don’t plan to use that computer for gaming anyway. I think this motherboard has “Energy Saving Mode”… so maybe if I activate it it will put some sort of limit on the CPU or something. I’ll come back and post what ever ended up happening. I also got 4 dollar back up Celeron processor just in case.

        • Your motherboard also supports a QX6850 (which is 130W), so the 120W definitely won’t damage your motherboard.

          My guess is that the X5450 may use slightly more power than an E5450 (due to probably using a slightly higher voltage), but I doubt it will come close to needing 120W. It’s identical internally to the E5450 (same stepping and everything), so Intel is probably just being conservative. However, I haven’t personally used any of the X5xxx Xeons, so this is just a guess.

          • Oh great! I hadn’t noticed that “Core 2 Extreme”processor series, I thought those were the same as the Core 2 Quads. Thanks for the info, I am pretty sure it will be fine then. It will all come down to how steady my hands are while making those modifications.

            I don’t understand what people use these processors for, or why they would want to replace them and resell them for such a small fraction of their original price. The Intel Core processors, were initially cheaper and are still being sold much more expensive than these Xeon processors. Is it simply an issue of supply and demand or is it also that these Xeon processors are probably very close to the end of their “life expectancy”?

        • It’s probably just supply and demand. Xeons were used in workstations at businesses and for servers, and I guess a lot of businesses are upgrading their systems due to Windows XP support ending in 2014.

          The companies that were the target for these types of processors probably aren’t buying them anymore, so there’s a lot more supply than demand.

          As more people find out about this mod, the prices on the Xeons will probably go up, but since this mod is geared toward enthusiasts, I’m sure the Xeons will always be a decent amount cheaper.

  3. hi is it possible to build a computer from scratch like this considering you cant update the bios before powering it on.

    • Hi, yes, you could, but you’d need to be careful.

      You’d either have to buy a motherboard that supports the Q9650 with its initial bios or buy from a seller that tells you the current bios version, so you can verify it’s compatible with the processors you want.

  4. I have a motherboard Intel Skulltrail D5400XS, is can increase the multiplier of the CPU Xeon X5460? Let me know. Thanks and regards

    • The X5460 doesn’t allow you to change its multiplier directly (like an extreme CPU does), but you can overclock it if your motherboard supports increasing the FSB.

  5. Installed Xeon E5440 on Gigabyte P35-ES2L, works fine.

    There is one problem. FreeBSD works well, but SuSE Linux doesn’t. It looks for CPU #1.

    I’ll try Windows Vista.

  6. I believe I have great news for Dell Optiplex 755 owners. Just yesterday I installed a Xeon X3363 CPU and my 755′s BIOS version A21 recognized the X3363 right off the bat. However, I found it a bit odd that as the operating system (Windows XP SP-3) started to load–a blue screen appeared and stopped the OS from loading. So I then decided to reinstall the Windows XP OS and now this computer boots to BIOS, loads the XP OS and functions as if it was made to run on Xeon CPUs.

    Perhaps someone may know why the OS failed to load necessitating the need to reinstall the OS–for I never had to do this when I installed Xeon E5440 CPUs in my Optiplex 330 and 360 rigs. Hopefully anyone who desires to attempt this swap has the OS start up disk if an OS reinstall is necessary to complete this install.

    This just proves that the person who discovered that Qxx series chipsets–in this case the Optiplex 755′s Q35 Express Chipset (ICH9DO)–does support 3xxx series Xeon CPUs because of their uni-processor configuration–since I mistakenly assumed that the 755′s motherboard had dual-processor support–which it clearly doesn’t. So major props to whoever discovered what many, including myself, overlooked. I tried installing Xeon E5450 and E5440 CPUs in my 755 but to no avail. A major bummer I thought, up until just yesterday since I own 5 Optiplex 755s. Now I am eagerly looking forward to installing Xeon X3363 CPUs in all of my 755 rigs.

    • In case anyone is interested, here’s the CPU-Z validation for my Dell Optiplex 755 Xeon X3363 install: http://valid.canardpc.com/dxczhe

      Note that the CPU-Z ID “Name” box states “E5440″ yet make no mistake that the 755 will not recognize 5xxx series processors in my experience. If you look down to the “Specification” box it more specifically reads “Xeon X3363″.

      Also notice that the CPU is running a bit hot since my 755 has stock cooling and I submitted the validation when the CPU was under load. I plan on fitting an aftermarket cooler and using Shin Etsu thermal compound to keep the temp down.

    • Thanks for the update, Mark. That basically confirms what I expected about the Qxx series. I’ll add this to the compatibility section.

      • I should be the one thanking you since I feel a sort of moral imperative to express my gratitude for your insight–for all I did was reconfirm what you already knew in theory–I just needed to put that knowledge you have shared with us into practice. I tried googling the topic of whether it’s even possible to install an LGA 771 Xeon in an Optiplex 755 and came up empty handed every single time. Without your guidance I would have given up trying to find a Xeon CPU that’s compatible with my 755–and would have had to settle for much more costly Core 2 Quads. Again, sincerest thanks.

    • I just remembered that I cleared the CMOS prior to installing the Xeon X3363 CPU into my Dell Optiplex 755–so perhaps this was what caused my computer not to load the OS and the resultant blue screen.

      On my next X3363 install, I’ll try installing the CPU without clearing the CMOS to see if I still get a blue screen.

      • I recently installed 2 morel Xeon X3363 CPUs in 2 additional Optiplex 755s without clearing the CMOS and both booted to BIOS and operating system perfectly without a blue screen–so I’m guessing that clearing the CMOS without making the proper BIOS adjustments was probably the culprit.

        I now have 3 Optiplex 755s running on X3363s!!!

        • Yeah, the blue screens probably had to do with the SATA hard drive setting in the bios. If that’s changed from what it was when windows was installed, your system won’t boot.

  7. For those who plan on installing a Xeon E5440 CPU in an Optiplex 330/360–I would suggest that if possible, you use a SLANS version of the E5440 instead of the SLBBJ version. From personal experience, when I installed the SLANS version E5440 CPUs in an Optiplex 330/360, these computers booted up and ran normally.

    However, recently I’ve tried installing SLBBJ versions of the E5440 and my Optiplex 330 and 360 and both showed this warning message at startup: “System does not support the installed processor.” While pressing the F1 key as instructed to do to continue will allow for the operating system to load and the computer to function–in the case of the 330, its CPU fan runs constantly at full blast, although I believe this has nothing to do with the CPU overheating since the core temps for all four cores register in the low to mid twenties Celcius at idle. I’m guessing that this probably has something to do with the difference in S-Spec numbers or Core Stepping of the SLANS and SLBBJ versions of the Xeon E5440.

    • Yeah, it sounds like the E0 stepping microcodes are missing from the bios. A bios mod will probably fix this problem, but most of the tutorials are based around AMI and Award bioses.

      Thanks for the heads up. I’ll mention this for both of those systems.

      • Agreed. A kind, generous and ingenious fellow from overclock.net said that he was willing to guide me through the entire process of modding the Optiplex 330′s BIOS and assist me step-by-step in adding the right microcode. However I told him that it would be much easier for me to opt for a SLANS E5440 than attempt to install a SLBBJ E5440 which appears to require a BIOS mod–for I have very limited programming experience especially when it comes to extracting, inserting and removing microcodes. I’d much rather swap CPUs, motherboards, or any other hardware out of the 330 rather than tinker with the CBROM. Heck–I’d rather even unsolder the BIOS chip and solder another one in if that was what it took.

  8. Olala, got also an offer for an E5450. The E CPUs have the Advantage in the lower max Temperature. Is this right? So in case of OC an E CPU will this be better than a X CPU?

    • The E5xxx series processors will probably require less voltage and have lower temps for the same speed, so they may overclock better, but it all depends on the individual cpu.

  9. Hello. I was told by a computer science graduate that you can use a 1600 mhz cpu in a 1333 mhz mother board. He said the cpu just downclocks to 133mhz. What is your opinion?

    • I’ve heard someone else mention that before, and it sounds like that would probably be true (if the bios had the microcode for that stepping of processor), but I haven’t personally tested this myself, so I’m not sure.

      You probably already know this, but if the fsb downclocked to 1333, it would also slow the processor down because the processor’s speed is a multiple of the FSB speed.

  10. This is the best explanation of CPU and Motherboard compatibility that I have ever seen.

    I have learned the hard way over 10 yrs. of bad experiences about compatibility.

    Thanks for being complete and thorough.

  11. Has anyone tested the QX9775 yet to see if that processor works as well? My motherboard supports up to the 1600MHz FSB of the QX9770 so I was wondering if this could work as well with this converter.


    • I never knew that was an LGA 771 processor until just now.

      Based on the CPUID of that cpu, it should work if your motherboard’s bios supports the C0 stepping Q9550 (and high TDP processors like the QX9770 or QX9650).

      If your system supports the Q9650 it also probably supports the C0 stepping Q9550, since the Q9650 is newer.

  12. Let me preface this post by stating that I am a novice overclocker.

    X5460 SLBBA cpu running stable on ASUS P5G41T-M LX Plux mobo @ 3.56 Ghz (375.1 X 9.5)

    I was running a QX9650 on this mobo, but due to the FSB (375 max stable in Prime95) and cpu vcore limitations of this mobo, the QX9650 was not reaching it’s potential. I could only achieve 3.6 GHz with the QX9650 due to insufficient Vcore I suspect. So I decided to swap out for a $45 X5460 and try to sell the QX9650 while they are still selling at close to $200 on ebay. With the X5460 I do get a bootup message to “update BIOS to get the full potential of this processor”, but according to the ASUS website I currently have the updated BIOS (V502 10/21/2011). Other than a bootup message, everything runs fine. The X5460 runs a little hotter than the QX9650, but still within design limits. Probably due to the generic thermal paste that I used. Still tweaking this setup as of now, and I may be able to reduce the Vcore with this cpu to reduce operating temps.

    Any tips for overclocking this mobo would be much appreciated.

  13. hello if I install xenonE5430 instead intel core 2 e7200 to be noticeable difference in games?

    • It depends on the game. Some games use more than two threads and some don’t. For games that do, you should notice a difference.

  14. Here it is:

    As you can see, I called 0803 since the last and latest asus version is 0802.
    I scanned it for viruses already but feel free to check again.
    It’s a .ROM file for P5QL-EM that contains latest bios and microcodes for the LGA771 cpu microcodes.
    Using the “ASUSupdate” facility under windows, select flash bios from file . select that 0803 file and you should be done . Reboot.

  15. ASUS Striker II Extreme finally working :)

    Motherboard: Asus Striker II Extreme Rev. 1.02G
    Chipset: nForce 790i ULTRA SLI (C73XE Rev. B1)/(MCP55P Rev A3)
    Max FSB: 1600
    Max TDP: At least 136W
    LGA 775 CPUs Supported: Q9650, QX9770
    LGA 771 CPUs Supported: All
    Xeons Tested: E5472 (SLANR – C0 Stepping) 1600 FSB

    Here is a patched bios for this mainboard (Asus v.1402, last bios for this mobo) with the last intel 771 microcode at the moment.


    PD: I had problems with the instalation of the chip, so be really really careful to properly cut the Mainboard plastic pins, or, as I did, make the new holes in the chip with the right size.

  16. Could it be that the reason underlying CPU support could be a sensing pin in the LGA socket sensing the DP support status for the Qxx chipsets vs the E5000 series Xeons? AMD used the addition of a pin to make the dual-processor-compliant Opterons a socket 940 so to be able to be used in a multiprocessor environment– marking the 8xx series 940′s as able to be used in quad-CPU environments. however the 8xx series quad-CPU chips could be used in a dual-socket board without any issue whatsoever.

    it makes me wonder if the same thing is happening here with a sensing pin those Qxx chipsets have.
    Has anyone looked into this yet, and tried to just add the proper microcodes to the BIOS to support them anyway and then try it regardless?

    • Yes, it’s definitely possible that’s what’s going on here, and there may be a way to get around it, but I haven’t heard of a way yet.

      People have tried adding the Xeon microcodes to the bios to get 5xxx series to work on these chipsets, but it didn’t work.

  17. Hi!
    Xeon l5420 on ASUS P5KPL-AM Rev. 2.03 working.
    But comp telling me to update my bios.

    • Please take a look at the troubleshooting section on this page. It explains how to get rid of the update message.

    • I updated cpu microcodes in mybios and all works!
      but cpu is very, very hot :( up to 80 degrees under load
      my old cpu 8600 is much colder

      • Yeah, the quad core cpus do get hotter than dual cores, but the temperature sensors are different in Xeons than regular cpus because the tj-max is different (and tj-max is how the programs calculate the temp).

        Unless you’ve manually set the tj-max in your temperature monitoring program, it probably isn’t accurate, and your real temperature is likely lower.

  18. hi donnie i just been looking around about this bsel mod on the 775 skt motherboards
    its basicly a mod of the cpu getting a peice of copper tape and connectiing to point together making the computer run in a higher fsb could this possibly still work after i put a X3363 skt in??? if not i can try it and let you all no?

  19. Hi,
    I have g41c-gs motherboard(current cpu i2 Duo E6300). I just bought the adapter and E5450 SLANQ processor for 47$ to try this mod. But it’s unclear to me how i can check if my bios version support this? in the motherboard website it says support Q9650(E0) ‘Since BIOS All’. Does it mean it should work without any problems?

  20. Hi,

    I putted X5160 on Dell Vostro 200s, And works great! G33M02 is not supported core 2 quad CPUS. I fixed the bios to AHCI mode, Use for run Mavericks.

  21. Got my Xeon E5440, its working fantastic in my Biostar TP43D2-A7 mobo, no bios update or anything works straight with all features. Very good purchase!

    Heres my validation: http://valid.canardpc.com/kdvqfk

  22. Hoping someone can help me out with this. Since I don’t really have the money to buy a new PC I decided to try this update on my HP Pavilion a6303w with asus IPIBL-LB motherboard.

    Based on the specs, and the fact that I’ve seen threads where others have successfully used this CPU in this motherboard, I purchased a used Xeon X5460 (3.16 Ghz) off ebay.

    Prior to installing the cpu I upgraded my BIOS to the most recent version available via the HP website.

    After installing the 775 to 771 sticker adapter mod and the Xeon MY CPU fan spins at max speed. However Windows 8.1 did load and I noticed the new CPU showed up in CPU-Z but not under “This PC/My Computer” in Windows. (It still showed as the old dual core that came with the PC). Also in CPU-Z the newly installed Xeon showed as Cores: 2 which I thought was weird. Eventually the CPU spun down to a more normal volume in windows. To verify everything was OK I shut down my pc properly and went to reboot my PC, but now it refuses to boot.
    My PC won’t load windows with the new Xeon installed now at all. It will start up and the cpu fan immediately kicks on to full max speed (Ludicrous speed: GO!). The PC starts to boot, loads up to the HP splash screen where I have the option of entering bios setup, recovery mode etc and then it will start to load windows. Upon attempting to load windows 8.1 it will then crash to a black screen, momentarily flash some sort of error message that disappears far too quickly to read and then reboots. It just continues with the boot loop a time or two until Windows figures out the PC hasn’t started correctly and it attempts an emergency repair to fix the startup problem. Of course that doesn’t work b/c the PC ultimately crashes when it attempts the repairs.

    If I swap out the Xeon for the stock CPU the PC loads and all is well. I just can’t get this thing to work with the XD5460 now no matter what I try. I’ve tried resetting the bios via jumpers and removing and reinstalling the CMOS battery. Neither worked.

    I’ve tried reseating and reinstalling the Xeon, each time with the same result. It simply won’t boot into Windows now.

    I’d chalk this up to a bad/incompatible cpu from the ebay seller but it worked upon the initial installation. In BIOS it lists the cpu as the Xeon X5460. I can access HP’s diagnostic utility at boot and the Xeon CPU passes the CPU test there (for whatever that is worth.) That leads me to think the CPU is ok but there is just something keeping things from booting properly.

    I’m thinking possibly I shouldn’t have updated the BIOS and that it may have something to do with that. I wanted to try rolling back the bio, but the original BIOS I had isn’t listed on the HP site (only 2 upgrades) I decided to try installing the oldest bios available on HP’s site for this PC. Of course this gave me problems too! The HP bios updates come in the form of a Windows based executable file. That’s fine but the problem is they won’t install the bios downgrade since I have a newer version installed already. It also complains my PC doesn’t meet the minimum requirements to install the BIOS. (Specifically citing my version of windows) The requirements for this BIOS (just like the newest version that DID successfully install) is Windows 7 and below. I suspect the older BIOS version executable is looking for the version of windows or lower that was available back in 2009. Since it sees Windows 8 it must assume it’s incompatible instead.

    At any rate I’m stuck now and can’t get the Xeon to work right in this PC. I have a suspicion it’s something with the BIOS but I’m obviously not all that knowledgeable. HP only offers one older BIOS version and I can’t install it via Windows.

    Does anyone have any ideas on how I can get this Xeon back up and running on my system? Or where to start? Any help is greatly appreciated.

    • Hi, I also recommend trying to load the default settings in the bios like Jansen said.

      If that doesn’t work, you should try reinstalling Windows. It sounds like the first time you booted with the new Xeon, Windows noticed it and tried to make some changes to work with the new hardware, and it sounds like that failed. Reinstalling Windows has fixed problems similar to this for others.

      If you don’t want to reinstall Windows, you could also try restoring the computer to its last known good state.

      If that doesn’t work, a bios mod to add the exact LGA 771 Xeon microcode may also help (http://www.delidded.com/lga-771-to-775-adapter/#where-to-get-a-modded-bios).

      • Thanks for the reply Donnie,
        I’ve done some more research and as we’ve suspected, I think it may be because Windows 8.1 is known for being very picky as far as what CPU it sees and I need to mod the BIOS to hopefully correct things. (I’ve heard Windows 8.1 won’t even install unless there’s the proper 771 microcode installed.

        I’ve managed to pull the error messages the PC flashes just before it crashes and reboots: “Your PC needs to restart. Please hold down the power button.” It then typically shows two error codes either:
        Error Code 0x0000005D
        Error Code 0x0000004C

        Both of which have to do with incompatible CPU or virtualization from what I can tell.

        I don’t want to reinstall Windows unless it’s necessary (I’m fairly confident it won’t install with the Xeon CPU installed anyway) so I’ll check the info on the link you provided and see if I can get anyone to help me with HP’s locked down BIOS. Thanks!

        • Yeah, it sounds like a bios mod will probably help.

          But you may also want to check to see if your bios has an option to enable the NX (no execute) bit. Windows 8 requires that, and it will throw the error code 0x0000005D (Your CPU is not compatible) if it doesn’t see that enabled.

          • Yeah I tried checking that before I posted here. My BIOS has the option to enable and disable XD for the cpu. It was already enabled but of course I disabled then re-enabled to be sure. Glad to hear my research was good and I’ve been trying all the right things though lol!

            I posted over at the forum you recommended. Hopefully someone can come through with a way to help me.

            Thanks so much for the quick responses and the suggestions!

      • It definitely does seem to be something Windows is doing upon the first boot with the Xeon installed. I reinstalled the stock dual core and did a system restore earlier to a point before I first installed the Xeon). After the restore was complete I powered off, installed the Xeon again and sure enough Windows booted right up. Still the issue with it not being recognized in System info however. Upon reboot it won’t start and then just continues in a bootloop. I also read somewhere that you can try deleting all CPU’s in device manager and then reboot to try to force Windows to recognize the Xeon. Didn’t work. (Same bootloop/not loading Windows issue)

        No help/replies over on bios-mods but I’ll give it some more time before I start searching for help elsewhere.

    • Have you tried disabling intel virtualization?

      • I have not. I remember reading something about virtualization being a reason these Xeons don’t work in some intel boards but I saw quite a few posts of people using this or similar CPUS in this same motherboard without much issue. Maybe they weren’t running Windows 8?

        I know one of the error codes looks like it’s commonly associated with issues relating to virtualization in Windows Server 2012. I’ll have to dig into that and see how to disable it.

        It definitely seems to be something Windows is doing upon the first boot with the Xeon installed. I put the stock dual core back in and did a system restore earlier this afternoon (to a point before I first installed the Xeon). After the restore was complete I powered off, installed the Xeon again and sure enough Windows booted right up. Still the issue with it not being recognized in System info however. Upon reboot it won’t start and then just continues in a bootloop. I also read somewhere that you can try deleting all CPU’s in device manager and then reboot to try to force Windows to recognize the Xeon. Didn’t work. (Same bootloop/not loading Windows issue)

      • I don’t see anything in HP’s stupid restrictive BIOS that addresses intel virtualization. I”m assuming I would need to disable it via BIOS?

        Windows virtualization (Hyper-v in Win 8) is disabled so that shouldn’t be an issue.

        • What type of bios does your system have?

          • it’s AMI via HP and you can do very little except change boot order etc.

            Good news on adding microcode though! I got help and someone injected the proper 771 codes to the BIOS. After giving myself a crash course on flashing BIOS via USB and AFUDOS I was able to flash the BIOS to my PC. It now boots up fine and the fan runs normally (Not constantly on fullspeed)

            The only thing is CPU-Z still shows this as 2 cores. Within Device Manager and everywhere else within Windows the PC still refers to the old E2140 Pentium Dual Core. The nXeon isn’t recognized in Windows at all.

            Now it’s time to for me to figure that out. At least we’ve made some great progress thanks to delidded.com and bios-mods. Thanks for the help so far!

          • Great.. glad to hear you got the bios mod. I’d now try going into the bios and loading the default settings.

            If that doesn’t work, try resetting the bios through the jumpers on the motherboard or by removing the CMOS battery.

          • Just thought I’d return to follow up on this ongoing saga for anyone else that may be experience similar issues.

            First of all one of the suggestions to fix this issue was reinstalling windows. That turned out to be what resolved the issues. NOTHING I tried would work to get Windows 8.1 to fully recognize the processor. Bios showed it as a Xeon Quad Core, but once windows booted it showed up as the old dual core. Testing with CPU-Z showed it operating as a dual core. I even confirmed with the Intel Processor Diagnostic tool, the newly installed Xeon Quadcore was being bottlenecked and treated by windows as if it was the 1.6 something GHz dual core.

            I spent a day and a half trying the usual remedies. No amount of bios resetting, processor uninstalling, msconfig editing, driver updating or other commonly seen suggestions would work. Ultimately the only way to fix things was a clean install of Windows 8 with the CPU installed from the get go. If you’re attempting this on this motherboard with a windows 8 installation do yourself a favor and just accept a Windows reinstallation as the quickest and easiest solution. Once I reinstalled with the CPU in from the beginning Windows recognizes the CPU and all 4 cores and so does CPU-Z.

            Problem Solved….sort of. As I feared Windows 8 ran great, but now I can’t update to Windows 8.1. I came across this in my other reason and I just KNEW I was going to see this when things went smooth as silk with the Windows 8 reinstall. After verifying everything was stable in Windows 8 I decided to install the 8.1 upgrade. The Windows 8.1 Setup program does a check to make sure your CPU meets the new requirements of 8.1 that aren’t shared with Windows 8. Upon attempting to install Windows 8.1 I was greeted with the message:
            Can’t Install Windows 8.1 because your processor doesn’t support CompareExchange128. Now I’m 90% sure I verified somewhere in my earlier research that The Xeon X5460 DOES support compareexchange. I’m guessing this is a motherboard issue and that the motherboard doesn’t support CompareExhcange 128 since it’s an older IPIBL-LB board.

            I won’t pretend to understand what CompareExchange128 is. I do know people who have encountered this on servers and within VirtualBox have overcome the issue with a few command line entries to active it.

            I’m guessing this is something that has to be enabled in bios for a motherboard to support it. I’m researching further but I know there are plenty more knowledgeable people that visit this site. Does anyone know if it is possible to get someone to enable CompareExchange128 with a Bios mod for the IPIBL-LB (Benicia). Other solutions?

            Thanks for everyone’s help (Especially Donnie and Jensen!)

            For the moment I’m stranded on Windows 8 until I figure out if there’s a way around the Windows 8.1 CompareExchange128 issue on this board.

          • I just read that CompareExchange128 is only needed for the x64 version of Windows 8.1 (but I haven’t verified this), and that you should be able to install the x86 version. If you’re using 4gb or less of ram x86 should be fine.

            There is a way to override many of the installation checks (http://forums.mydigitallife.info/threads/37517-Q-Win-8-bypass-PAE-NX-SSE2-check/page12?p=771750&viewfull=1#post771750), so you may want to check that out. It looks like it’s for Windows 8, but it may also apply to Windows 8.1.

            Either way, the guys at mydigitallife probably know a lot about this type of thing, so you may want to try asking there. A google search for “windows 8.1 CompareExchange128″ also turned up a bunch of stuff.

          • You’re right. I forgot to mention I’m running the 64 bit version of Windows to take advantage of 8GB of ram. The 64 bit version of windows 8 doesn’t require CompareExchange but the 64 bit version of 8.1 does.

            I believe the installation checks over-ride just skip the checks but if the PC actually needs the feature it checks for it will encounter problems. I’ll look though the link you provided though.

            I’ve done some quick searches and I’ve seen most of it dealing with virtual box and issues on Servers. I’ve also seen the issue where the processor supports CompareExchange but the MB doesn’t due to outdated bios/firmware. Leading me to at least hope there’s a way to enable it via a Bios mod.

            I’ll see what I can find out on my own. Just always worth asking if I don’t find what I need with a preliminary google session. Thanks!

          • Here’s an update for anyone following along with this problem.

            We figured out why Windows 8.1 was saying the CompareExchange128 instruction was missing even when the X5460 supported it. It turns out that whoever did the bios mod to add the Xeon microcodes for SingleDad messed up somewhere. When we readded the microcodes correctly, Windows 8.1 correctly recognized the processor and installed without a problem.

            For some reason, it wouldn’t work right until Windows was reinstalled, but this may be due to the motherboard he was using.

  23. I apologize for the novel posted above, but I just wanted to make sure I gave all pertinent info I could think of! ;)

  24. @Singledad i had the very same issue booted up normally windows 7 but had also just 2 cores recognized in cpu-z or anywhere else with my E5440, but in device manager it showed 4 cores, then after restart it would just freeze on the windows logo loading, i fixed it by loading optimal defaults in BIOS!! if it doesnt work try messing around with some settings in the BIOS, also ensure you set AHCI in BIOS if you had it before on AHCI and if you reseted the BIOS!

    • Thanks for the reply Jansen,
      I’ve tried all of your suggestions. Rest the bios , tried changing the SATA from RAID to AHCI etc. I may try to find someone to help me inject the exact code into the BIOS…but of course HP makes updating the BIOS on this difficult and I’ll need to find some help extracting the right files from the executable files. Thanks for the reply. I’ll keep you posted if I figure it out and if you think of anything else let me know.

  25. Just put an E5450 (C0 stepping) into my Asus P5Q SE PLUS works but got the message
    ” to unleash full potential of this CPU, update your BIOS”
    I used the guide provided to inject the microcodes and it works .

    Hi, it is me again. This time I have successfully installed a Xeon E5450 C0 on INTEL DP43TF
    Very happy with results. :)

  26. @ mike – no, don’t do that! This mod isn’t about shorting those two pins, it is about swapping them! Use a proper adapter, they are cheap and easy to obtain.

    • I think that Mike was talking about doing something else (not shorting the two pins swapped by this adapter).

      There’s another mod for increasing the FSB of your motherboard if you don’t have a bios that allows overclocking.

  27. Asus Striker II NSE – latest bios 0901 modded for Xeon

    Not stable with Xeon chip, tried 2 different chips L5430 & E5450 both work in other boards.

    POSTs and boots fine, then random reboots, BSOD, lock ups etc.

    Not recommended despite chipset being marked as compatible. Tried both windows and linux.


    • Forgot to mention board works great with a 775!


    • Have you tried resetting the bios through the jumper on the motherboard or by removing the CMOS battery? Have you also loaded the default settings in the bios after installing the Xeon?

      These things usually fix random reboots, BSOD, and lock ups if you’ve already added the Xeon microcodes to your bios.

      • Yes, tried all of those things. I normally start with a full reset bios to failsafe. then cold boot. Checked seating of the chip a couple of times and happy with it. Works perfectly in other boards.

        Just flaky, sata issues, network issues, CPU lock ups. everything detected perfectly all features enabled all looks good. But just unstable. Very difficult to debug, as even kernel logs just stop with no waring, immediate reboot. Comes back up fine. Very frustrating.

        Anyway abandoned in favour of Gigabyte P45 chipset board. Which is rock solid with the same chips.

        GA-EP45C-DS3R (rev. 1.0)
        Intel® P45 + ICH10R Chipset

        Latest EP4CDS3R.F6a Bios modded with x0b codes for the 1067a processors.



        • Thanks for letting us know. I haven’t heard of any other problems with the 790i chipset, so I’m hoping this was an isolated incident with your motherboard, but I’ve removed the 790i from the compatible chipset list for now, and I’ll keep an eye on it.

  28. I’m eyeing a Xeon X5460 for a cheap upgrade: is there any reason why a C0 vs. E0 stepping should matter? This is for a GA-EP35C-DS3R (rev. 2.1) that I already know runs an E5450 C0 stepping perfectly (which will be moved to another board that can’t go any higher than E5450). My research shows that E0 change is just this: “Changes in E0 stepping: new XSAVE and XRSTORE instructions, ACNT2 feature used for determining processor utilization, halide-free package.” I think it probably won’t matter, but I figured I’d ask anyways. Also, I’m wondering if 771 sellers are catching on to this particular trick: I now can’t find an X5470 for really cheap prices anymore. Anyone else notice higher prices recently?

    Other query (purely theoretical): Xeon ES chips seem to usually have unlocked multipliers…would this allow for significantly higher overclocking, or are ES chips inherently more unstable?

    • E0 is newer and seems to overclock better, but some systems don’t support it (it should work if your system supports a Q9650).

      Yeah, the prices have definitely gone up some due to this mod.

      I’m not sure about the stability of the engineering sample cpus, but it should definitely help you overclock higher if you’re limited by the fsb your motherboard can do. Many P35 motherboards can only hit a little above a 400fsb, while the P45 can do much higher.

    • I was shopping for the same processor about a week ago. I can definitely tell you sellers have caught on and aren’t letting the Xeons go cheaply. I too was looking at the X5470 and couldn’t find one at a price that made sense for updating a dated rig. $75 to $100+ seems a little steep for a used processor that’s 8 years old. After a few days of searching I gave up on the X5470.

      I chose the X5460 because it was more available and the prices were more reasonable for a used CPU. I decided there wouldn’t be a huge noticeable performance difference between the two for me. On fleabay there were a few sellers that had multiple Xeon X5460′s with a “Best Offer” option. Thinking these guys with a handful of these (probably pulled out of scrapped servers for free) would be willing to budge on price proved to be comical. I put in a few different very reasonable offers for a X5460 from a few different sellers. Let me tell you they don’t budge on price. Many of them were $65+ and I’d offer around $45 to $50. Still fair with room for the inevitable counter offer from the seller. Two of them counter offered for like $3-5 less than their full asking price. The other just flat out declined my offer. The sellers (at least on ebay) aren’t budging an inch and the price just seems to keep rising. Your best bet is to search more locally or if you have time to spare just wait for the rare lucky steal on ebay. There’s always someone who doesn’t know or who will under-price to move it fast. The problem is all of us waiting for the same person! ;)

      • @SingleDad

        Very true! Just a few months ago I purchased E5440s with relative ease for $26, E5450s for under $37, and the even faster X3363s for under $35 on eBay!

        While E5450s can still be found for around $40 each if you buy them in pairs on eBay–you would be hard pressed to find any E5440s for anywhere near $26–and completely down on your luck in finding X3363s for anywhere near $35 because of the limited supply of X3363s and the realization that the X3363 is one of the fastest Xeon CPUs that will work in an LGA 775 board. I’m kicking myself because just 2 weeks ago, a pair of X3363s were auctioned of on eBay for $76.49–a steal considering these CPUs sell for approximately $75 each.

        Thankfully I stumbled across this delidded site and purchased the all the Xeons I needed before demand would outstrip supply and drive up prices.

  29. Hi guys. Maybe someone know,or this mod works on P5K3 motherboard? This time i running on Q9550 and P35 chipset.

  30. EVGA 680i works with all 1333mhz xeons i’ve teste, including e5420 (45nm, 12M, 1333).
    works fine, no issues…

  31. Hello!
    Motherboard MSI P35 NEO 3
    Xeon X5450.
    Everything works fine. But there is one problem. Windows 8.1 (64) can”t be installed: “You can’t install Windows 8.1 Preview because your processor doesn’t support CompareExchange128.”
    I had to install Windows 8 64bit.

  32. Hi, I will try XPS 720 as nForce 680i chipset, I read a details with your guide. Does not supported 45mn XEONs. Few guys succeeded X5460 on it, no issues. Let me know how about it?

    • Yeah, it works for some and doesn’t work for others with a 680i chipset, so that’s why I mentioned that.

      The 680i chipset doesn’t officially support 45nm quad core cpus (even regular LGA 775), but some motherboard makers unofficially support it, which is why it works for them.

  33. Just wanted to say thanks. I just installed a x5450 on an older EVGA nForce 680i SLI.
    Board part number 122-CK-NF68 – nforce 680i SLI using bios P33-ISO dated 12-01-2009.

    Works great, windows shows it as a X5450 running at 3.0. Speed Step works to clock it down to 2.0 at idle. CPUz sees the it correctly and shows it as a socket j 771.

    I was able to get it to run at 3.6 just by bumping the FSB to 400×9. Runs great although due to my cheap cooler it gets hot 70c+. at stock speeds it stays around 60 under load.

  34. Another working mod confirmation by me:

    mobo (same as before): ASUS P5Q3 Deluxe
    processors: E5440 C0 (two chips) and X5450 E0

    Donnie pls update the data (don’t forget to add MSI P45 Neo2 that I posted on 1st April)

    • Thanks. I usually update the list at least once a week with all the latest information. I’ve just been really busy lately.

      I just updated it with everything up to this point.

  35. Current System:

    Core2Duo E6420 2.13@3.2 GHz (1600 FSB)
    EVGA 780i SLI with most recent BIOS P10

    Suggestions? Xeon X5470 or X5492? I’d prefer the X5470 due to his higher multi (x10) which makes ist better for overclocking. BIOS-Microcode-Update neccessary? I think it’s obsoltete with this build, isn’t it?

    Thanks in advance!!

    • I’d also probably go with the X5470 due to the higher multiplier.

      You usually don’t need a microcode update for most motherboards. Just if you’re having problems.

  36. Round 2….. I just installed another x5450 into an ASUS p5n32-e sli that’s a nforce 680i on newest bios 1903. I got the “CPU not recognized update bios to unleash full power” message just after post. Windows then blue screened and crashed like crazy. So I updated the bios micro-code like suggested. That removed the cpu message but windows still blue screens. I put my old cpu back in Q6600 and then did a check disk and memtest. Every thing ok. Put x5450 back in and blue screen. Any ideas?

  37. Just for fun I installed an old hdd and tried to do a clean install of windows. About 15 minutes into the install blue screen.
    I have another adapter sticker, is it possible that this is caused by a bad or poorly installed adapter?

    • Hi, the 680i chipset is known to not officially support 45nm quad core processors (this is mentioned in the motherboard compatibility section). Some motherboards unofficially support them but not all.

      I just checked the cpu support list for your motherboard, and it only shows support for up to a 65nm Q6700, so that’s likely why you’re getting the bluescreens.

      Your motherboard would need to support a 45nm Q9650 to support the X5450.

  38. Probably never going to work but is there a fix for “only works with P4 single core” issue with the Dell 8400? I keep seeing these scrap and it seems a shame to waste them.

  39. used the mod on a xeon X5492 3.4 processor and a Gigabyte GA-EP45-UD3L motherboard and worked slick as sht –thanks loads -revived a great mb

  40. I putted X5365 on old Dell vostro 220s, Works great. Run a Hackintosh Mavericks, No issues. I will try X5400 CPUS on same PC…

    I have a 2 X5365s used by Mac Pro 1,1 was in a closet now…lol

  41. Dear Donnie
    I’ve a main MSI P45 Neo 2, can i use it with x5472 & 5492, tks so much!

  42. E5402 and e5420 doesn’t work on Asus P5KPL-VM. BIOS detects it, past POST check, but after that – black screen and blinking cursor.

  43. Xeon E5410 work fine on Gigabyte GA-EP43-S3L. Now I’m trying run Hyper-V on win2k8 r2, but system show error that cpu have not vt-x but have. Any ideas?

Leave a Reply

Your email address will not be published. Required fields are marked *


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>