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 cheaper 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).

List of LGA 771 Xeon Processors (with current prices)

http://www.delidded.com/list-of-intel-lga-771-xeon-processors/

Where can I get an adapter?

For a current list of sellers (sorted by price), check out this page.

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 costs about $35 (about $100 less than the Q9650).

Other good deals on LGA 771 Xeons include:

For detailed specs on all of the Xeons and a full list of current prices, take a look at this page.

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, 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.

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

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 Northbridge chipset. You can usually find what chipset your motherboard has by looking at its specification list.

Chipset compatibility table

Note: For known compatibility issues and more details, please see the bullet points (which are shown right after the table).

Xeons that are compatible with this chipset
Chipset5xxx Series3xxx Series45nm65nm
P45, P43, P35, P31, P965
G45, G43, G41, G35, G33, G31
nForce 780i, 630i
GeForce 9400, 9300
YesYesYesYes
Q45, Q43, Q35, Q33
X48, X38
NoYesYesYes
nForce 680i and 650iYesYesMaybe (see below)Yes
Intel's 3200/3210 chipset (used in server motherboards)No???

If you don't need more details about the topics shown above, you can skip ahead to the next section: Next, make sure your BIOS supports a similar LGA 775 CPU.

What do 5xxx series and 3xxx series mean?

By 5xxx series we mean any Xeon whose model number ends in 5xxx (this includes all the E5xxx, X5xxx, and L5xxx processors).

My chipset isn't listed here. Will this work for my motherboard?

The mod will still likely work for you if your BIOS supports a similar LGA 775 processor.

If you do try it, please let us know how it goes by leaving a comment at the bottom of this page.

Some motherboards made by Intel don't work with this mod

Note: This information only applies to motherboards actually manufactured by Intel. We haven't heard of any problems with ASUS, Gigabyte, MSI, or any other brands.

For some reason, some Intel brand motherboards that have a compatible chipset and support a similar LGA 775 processor do not work with this mod (please see the list of incompatible motherboards for the model numbers).

So far, only some Intel brand motherboards with P35, G35, and G33 chipsets have not booted with a Xeon, and most of these motherboards (all but 1) also supported Intel Viiv Technology (which is used in media center PCs). We haven't heard of any reports of motherboards with G41 or newer chipsets having problems, but it's still possible some may.

Until we learn more, we don't recommend trying this mod on a motherboard manufactured by Intel that has a P35, G35. or G33 chipset (unless it is listed in the compatible motherboards list or you don't mind the risk that it may not work).

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.

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).

The E0 stepping E5440 and X3363 Xeons both have the same CPUID (1067A), which means they're both made from the same silicon and are basically the same internally. Additionally, there's no noticeable difference between them (other than one has dual-processor support), so it looks like this could be causing the problem. Some chipsets may be checking for this and may be blocking the system from booting.

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

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

Similar LGA 775 CPUsCoresProcessMax FSB (unless motherboard supports higher)Max TDP (unless motherboard supports higher)Compatible Xeons (if supported by chipset):
Q9650445nm133395WHarpertown (54xx)
Yorkfield-CL (33xx)
Q9550S445nm133365WLow voltage Harpertown (L54xx)
Q6700465nm106695WClovertown (53xx)
E8600245nm133365WWolfdale-DP (52xx)
Wolfdale-CL (31xx)
E6850265nm133365WWoodcrest (51xx)

* See this page for a full list of all the Xeon model numbers.

If you don't need more details about the topics shown above, you can skip ahead to the next section: Recommended LGA 771 Xeon processors.

How the compatibility table shown above works

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 the LGA 771 Xeons shown in the last column (if your chipset supports it).

You should only buy Xeons with a FSB and TDP less than or equal to the values shown (unless your motherboard supports higher).

Some Xeons have a higher FSB or TDP* than their similar LGA 775 CPU

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

Because of this, you need to make sure your motherboard supports the FSB and TDP of the Xeon you're buying. Some motherboards will not boot processors with a TDP 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
  • X54x2 series with a 1600 FSB has a max TDP of 150W

How to check what TDP your motherboard supports

Our motherboard compatibility list (shown later on this page) has max TDP numbers for many motherboards, so you should check there first.

If your motherboard isn't in our list, a good way to check if your motherboard supports 120W and above processors is to check its CPU support list. If your system supports overclocking or extreme edition processors (like the 130W QX9650), you should be able to run the 120W X54xx series Xeons (the 150W ones will also probably work). 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 lower 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 LGA 775 processors your motherboard supports

If you're unsure what LGA 775 processors your motherboard supports, 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)

Prebuilt computers (like Dell) sometimes use different motherboards (depending on what parts come with the system), and the motherboards may not support the same processors, so you'll need to figure out which motherboard you have.

You should be able to find the model number with CPU-Z.

Right now, the following 45nm Harpertown Xeons with a 1333 FSB seem to be the best deals. These are quad core and have high multipliers, which means they should also overclock easily.

For more prices and detailed specs on all of the Xeons, visit this page.

Tested motherboards

Below you'll find a list of motherboards that have been tested with this MOD.

We've also included some motherboards that should be compatible (based on their specifications) but haven't been tested yet. However, we clearly mark those as Not tested yet, so you can tell the difference.

Predicted compatibility

On most of the motherboards, we've tried to predict what Xeons will be compatible based on the motherboard specifications (like chipset, max FSB, and max TDP), supported LGA 775 processors, and the Xeons people have tested. The prediction should be very accurate in most cases, but since we haven't actually tested all of these ourselves, we can't guarantee it.

We recommend that you also verify compatibility yourself using our LGA 771 to 775 motherboard compatibility guide (which was shown earlier on this page).

Let us know if this mod worked on a motherboard that isn't in our list

Please leave a comment with your:

  • Motherboard model number (and revision if it has one)
  • Xeon model number (and stepping if you know it)
  • (Optional) chipset, max FSB, max TDP, and supported LGA 775 processors

This will help other people that are also using your motherboard.

MotherboardChipsetMax FSBMax TDPLGA 775 CPUs SupportedLGA 771 Xeon Compatibility
Abit AW9D-MAX975X / ICH7R1066At least 130WQ6700, QX6800 All 65nm Xeons with a 1066 FSB

Worked: L5320
Abit IP35 ProP35 / ICH9R1333At least 130WQ9550, QX9650 Probably all (within FSB limits).

Worked: E5420

Notes:
  • May need to update cpu microcode to support overclocking.
  • Need bios update to support E0 stepping 45nm Xeons
Abit IP35-EP35 / ICH91333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5472, E5440, E5420
Acer Aspire G7700nForce 780i1333At least 130WQ9650, QX9650 Should support all Xeons (within FSB limits)

Not tested yet
ASRock 4Core1600-GLANP31 / G311333 (or 1600 when overclocked)At least 136WQ9650, QX9770 All (within FSB limits)

Worked: L5420
ASRock G31M-GSG31 / ICH71333 (or 1600 when overclocked)At least 105WQ9650, Q6600 (all steppings) All (within FSB and TDP limits)

Not tested yet
ASRock G31M-SG31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, Q6600 (all steppings) All (within FSB and TDP limits)

Worked: X5460, E5410, L5430, E5345
ASRock G31M-VS2G31 / ICH71333At least 130WQ9650 All (within FSB and TDP limits)

Worked: E5410
ASRock G41C-GSG41 / ICH71333At least 130WQ9650 All (within FSB and TDP limits)

Worked: X5470, X5460, X5450, X5260
ASRock G41M-VS3G41 / ICH71333At least 130WQ9650 All (within FSB and TDP limits)

Worked: X5450, E5420, E5205
ASRock N7ad slinForce 740i SLI1600At least 136WQ9650, QX9770 Should support all Xeons

Worked: X5460 (SLBBA E0)
ASRock P43 Pro/USB3P43 / ICH101600At least 136WQ9650, QX9770 All

Worked: L5430
ASRock P43D1600Twins-1394P43 / ICH101600At least 136WQ9650, QX9770 All

Worked: E5430 (C0)
ASRock P43DEP43 / ICH101600At least 136WQ9650, QX9770 All

Worked: 51XX, 52XX, 53XX, 54XX
AsRock P43Twins1600P43 / ICH101600At least 136WQ9650, QX9770 Should support all Xeons

Not tested yet
ASRock P45R2000-WiFiP45 / ICH10R1600 (or 2000 when overclocked)At least 136WQ9650, QX9770 All

Worked: X5460 (SLBBA E0)
ASRock P45TSP45 / ICH101600 or 2000 (when overclocked)At least 136WQ9650, QX9770 All

Worked: E5430
ASRock P45x3P45 / ICH101600At least 136WQ9650, QX9770 All

Worked: E5440
ASRock P5D-BEP965 / ICH81333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5420 (E0)
ASUS CommandoP965 / ICH81066 (1333 beta)At least 130WQ9650 beta, QX9650 beta All (within FSB and TDP limits)

Worked: E5450 (E0)
Asus Maximus Formula (version 1)X38 / ICH9R1600At least 136WQ9650, QX9770, Q6700, E8600, E6850 All 3xxx series Xeons. The 5xxx series is incompatible.

Worked: X3363 (E0)
ASUS Maximus II FormulaP45 / ICH10R1600At least 150WQ9650, QX9770 All

Worked: X5492, X5450 (E0), E5450, X5460, X5470
Asus Maximus II GeneP45 / ICH10R1600At least 150WQ9650, QX9770, Q6700, E8600, E6850 All

Worked: X5492
ASUS P5BP965 / ICH81333 (with beta bios), 1066At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5450 (C0), E5440
ASUS P5B DeluxeP965 / ICH8R1333 (with beta bios), 1066At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5440 (C0), E5430
ASUS P5B SEP965 / ICH81333 (beta), 1066At least 136WQ9650, QX9770 All (within FSB limits)

Worked: L5420 (C0)
ASUS P5B-DEP965 / ICH81333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5450
ASUS P5B-EP965 / ICH8R1333 (beta), 1066At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5450
ASUS P5E-VM DOQ35 / ICH9DO1333At least 130WQ9650, QX9650, Q6700, E8600, E6850 All (within FSB limits)

Worked: E5410 (E0)

Notes:
  • 5xxx series Xeon worked even though the chipset was Q35
  • ASUS may not have the 5xxx series incompatibility problem
ASUS P5E-VM HDMIG35 / ICH9RAt least 1333At least 130WQ9650, QX9650 Should support all Xeons (within FSB limits)

Worked: X5450 (C0)
ASUS P5G41-M LEG41 / ICH7At least 1333At least 136WQ9650, QX9770, Q6700, E8600, E6850 All (within FSB limits)

Worked: E5420 (E0)
ASUS P5G41C-M LXG41 / ICH7At least 1333At least 95WQ9650, Q6600 (95W only) Should support all Xeons (within FSB and TDP limits)

Worked: E5405 (E0)
ASUS P5G41T-M LXG41 / ICH71333At least 120WQ9650, Q6600 (95W only) All (within FSB and TDP limits)

Worked: E5472, X5460, E5420 (E0), L5420, E5405
ASUS P5G41T-M LX PlusG41 / ICH71333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5450, X5460 (SLBBA)
ASUS P5G41T-M LX2/BGG41 / ICH7At least 1333At least 150WProbably Q9650 All (within FSB limits)

Worked: X5492
ASUS P5G41T-M SIG41 / ICH71333At least 136WProbably Q9650, QX9770 Probably all (within FSB and TDP limits)

Worked: E5420
ASUS P5KP35 / ICH91600At least 136WQ9650, QX9700 Probably all

Worked: E5440 (E0), E5450 (C0 SLANQ), X5450 (E0 & C0), X5460 (E0 & C0), x3363, E5420 (E0), E5430

Didn't work: X5482 (1 person reported this to be unstable, but it sounds like it may have been a defective cpu)
ASUS P5K DeluxeP35 / ICH9R1600At least 136WQ9650, QX9700 All

Worked: E5430, L5420
ASUS P5K PremiumP35 / ICH9R1600At least 136WQ9650, QX9700 All

Worked: L5420
ASUS P5K ProP35 / ICH9R1600At least 136WQ9650, QX9700 All

Worked: E5440 (C0), X5450
ASUS P5K SEP35 / ICH91600At least 136WQ9650, QX9770 All

Worked: X3363
ASUS P5K SE/EPUP35 / ICH91600At least 136WQ9650, QX9770 All

Worked: X5460 (C0)
ASUS P5K-EP35 / ICH9R1600At least 136WQ9650, QX9770 All

Worked: E5440, E5430, X5450
ASUS P5K/EPUP35 / ICH91600At least 136WQ9650, QX9700 All

Worked: E5440 (C0 stepping)
ASUS P5K3 DeluxeP35 / ICH9R1600At least 136WQ9650, QX9770 Should support all Xeons

Not tested yet
ASUS P5KCP35 / ICH91600At least 136WQ9650, QX9770 All

Worked: E5450, E5420 (E0)
ASUS P5KLP SEG31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770 All (within FSB limits)

Worked: L5410
ASUS P5KPL AM/PS (rev. 2.01G)G31 / ICH71333 or 1600 (when overclocked)150WQ9650, QX9770 All (within FSB limits)

Worked: X5482
ASUS P5KPL SEG31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770 Should support all Xeons (within FSB limits)

Worked: X5450, E5440
ASUS P5KPL-AMG31 / ICH71333 (or 1600 when overclocked)At least 136WQ9650, QX9770 All (within FSB)

Worked: E5450 (SLANQ), X5460 (SLANP), X5450 (E0), L5420
ASUS P5KPL-AM EPU (rev. 1.01G)G31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770 All (within FSB)

Worked: X5450 (E0), L5420
ASUS P5KPL-AM SE (rev 1.01G)?1333 (or 1600 when overclocked)At least 136WQ9650, QX9770 Should support all Xeons (within FSB limits)

Not tested yet
ASUS P5KPL-CMG31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770 All (within FSB)

Worked: X3323
ASUS P5KPL/1600G31 / ICH71333 or 1600 (when overclocked)At least 136WQ9650, QX9770 All (within FSB limits)

Worked: L5420
ASUS P5KRP35 / ICH9R1600At least 136WQ9650, QX9770 All

Worked: L5420
ASUS P5N-DnForce 750i SLI (C72P) / nForce 430 (MCP51)1333At least 130WQ9650, QX9650 Mixed results on whether the mod works well on this motherboard. See the notes below.

Worked: E5450, X5460 (C0)

Notes:
  • Two people have reported instability problems (not the ones in the working list) with X5460 (C0) and X5450 (C0)
  • Not sure, but may be due to not fully resetting the BIOS (through jumper or removing CMOS battery)
ASUS P5N-E SLInForce 650i1333At least 130WQ6700, QX6850, and unofficially Q9650 Probably all (within FSB limits)

Worked: X5450
ASUS P5N-EM HDMInForce 630i1333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: X5260
Asus P5N-MXNVIDIA GeForce 7050 / nForce 610i1333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5450 (C0)
ASUS P5N-T Deluxe (rev. 1.02G)nForce 780i SLI / nForce 570 SLI1333At least 136WQ9650, QX9770 All (within FSB limits)

Worked: E5450
ASUS P5P43TD (rev. 1.00G)P43 / ICH101333 or 1600 (when overclocked)At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5450, X5450
ASUS P5P43TD PRO (rev. 1.02G)P43 / ICH10R1333 or 1600 (when overclocked)At least 136WQ9650, QX9770 All (within FSB limits)

Worked: X5460
ASUS P5QP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: E5450, X5450, L5430
ASUS P5Q DeluxeP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: X5470, X5450, X5460 (E0)
ASUS P5Q PremiumP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: X5470
ASUS P5Q ProP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: E5450, E5462, X5460, E5430, E5440
ASUS P5Q Pro TurboP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: X5470, X5460, E5450
ASUS P5Q SE PLUSP45 / ICH101600At least 136WQ9650, QX9770 All

Worked: E5472 (E0), E5450 (C0 stepping), L5420 (SLBBR E0)
ASUS P5Q SE/RP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: E5450
ASUS P5Q SE2P45 / ICH101600At least 136WQ9650, QX9770 All

Worked: E5420 (SLBBL)
ASUS P5Q-EP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: E5450, X5470, X5460, L5430
ASUS P5Q-EMG45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: X5470, X5460 (SLBBA), E5450
ASUS P5Q-SE2 (rev. 1.00G)P45 / ICH101600At least 136WQ9650, Q6700, Q6600, QX9770 Should support all Xeons

Not tested yet
ASUS P5Q3 (rev 1.00G)P45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: E5450, E5472, L5430, L5420
ASUS P5Q3 DeluxeP45 / ICH10R1600150WQ9650, QX9770 All

Worked: X5470, E5450 (C0), X5460 (C0), E5440 (C0), X5450 (E0 & C0), E5420 (E0), E5462, X5482 (E0), L5420 (E0), E5472
ASUS P5QCP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: E5440
ASUS P5QD TurboP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: E5450 (E0)
ASUS P5QL PROP43 / ICH101333 or 1600 (when overclocked)At least 136WQ9650, QX9770 All (within FSB limits)

Worked: E5410, E5450, x3353
ASUS P5QL-EP43 / ICH10R1333 or 1600 (when overclocked)At least 136WQ9650, QX9770 All (within FSB limits)

Worked: X5470, E5450, L5420
ASUS P5QL-VM EPU (rev. 1.01G)G43 / ICH101333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: X5460
Asus P5QL/EPU (rev 1.00G)P43 / ICH101333 (or 1600 when overclocked)At least 136WQ9650, QX9770, Q6700, E8600, E6850 All (within FSB limits)

Worked: X5470
ASUS P5QLD PROP43 / ICH101333 (or 1600 when overclocked)At least 136WQ9650, QX9770 All (within FSB limits)

Worked: X5450 (C0)
ASUS P5W DH Deluxe975X ICH7R1333 officially, 1600 (may need overclock)At least 150WQ9650, QX9770 All (within FSB limits)

Worked: X5492
Asus P5WDG2 WS Professional975X / ICH7RAt least 1333At least 130WQ9550 (C0), Q6700, E8500 (C0), E6850 Probably all (within FSB limits)

Worked: X5450 (C0)

Notes:
  • CPU support list doesn't list the Q9650 as compatible, so E0 stepping Xeons may not be supported without a BIOS MOD
Asus PN57A-VMAt least 1333At least 120WAt least Q9550 (C0) Probably all (within FSB and TDP limits)

Worked: X5450 (C0)

Notes:
  • Couldn't find cpu support list, so can't verify if Q9650 or E0 steppings are supported
  • 1 reported they needed to disable "C State Tech" in BIOS to stop slow booting and high CPU usage
ASUS Striker ExtremenForce 680i SLI (C55XE) / NVIDIA MCP55XE1333At least 130WQ6700, E8600 65nm quads (officially), but reported to also work with 45nm quads

Worked: X5460
ASUS Striker II ExtremenForce 780i SLI (C73XE rev. B1)1600At least 136WQ9650, QX9770 All

Worked: E5472 (SLANR C0)
ASUS Striker II FormulanForce 780i SLI (C55XE)1333At least 136WQ9650, QX9770 All (within FSB limits)

Worked: X5470
Biostar G41 DVIG41 / ICH7133395WQ9550 (C1 stepping), Q6600 (95w only) All (within FSB and TDP limits)

Worked: E5450
Biostar G41D3+G41 / ICH7133395WQ9550 (C1 stepping) At least C0 stepping Harpertown Xeons (within FSB and TDP limits); Maybe also E0 stepping

Worked: E5430
Biostar P43D2-A7P43 / ICH101333 (not sure about 1600)At least 105WProbably Q9650 All (within FSB and TDP limits)

Worked: E5450
Biostar TP43D2-A7P43 / ICH101333 (or 1600 with overclock)At least 105WQ9550 (SLAWQ) Probably all (within FSB and TDP limits)

Worked: E5440
Biostar TP43E XE (ver 5.x)P43 / ICH101333 or 1600 (when overclocked)At least 136WQ9550 (E0 stepping), QX9770 All (within FSB limits)

Worked: E5472, L5420
Biostar TP45D2-A7P45 / ICH101333 (or 1600 with overclock)At least 105WQ9650, Q6600, E8500, E6850 Probably all (within FSB and TDP limits)

Worked: E5472, X5450, E5410 (C0/E0), L5408, E5310 (B3/G0)

Notes:
  • CPU support list is out of date
  • May need to add Xeon microcode
Biostar TPower i45 (ver 5.x)P45 / ICH10R1333 or 1600 (when overclocked)At least 136WQ9550 (E0 stepping), QX9770 All (within FSB limits)

Worked: X5450
Clevo D900CP965At least 1333At least 95WQ9650 Probably all (within FSB and TDP limits)

Worked: E5450
Clevo D901CP965 / ICH8RAt least 1333At least 95WQ9650 Supports all 3xxx series Xeons (within FSB and TDP limits). The 5xxx series may be incompatible.

Worked: X3363

Didn't work: E5450

Notes:
  • The E5450 and X3363 were both tested by the same person
  • I think this is a special desktop/laptop hybrid, so it’s definitely not a typical system.
Dell Inspiron 530 DG33M03 motherboardG33 / ICH91333At least 95WQ9650 All (within FSB and TDP limits)

Worked: E5440 (E0)
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.

Worked: 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.

Worked: E5440 (C0 stepping)
Dell Optiplex 380G41 / ICH7At least 1333At least 95WProbably Q9650 Probably all (within FSB and TDP limits)

Worked: E5450 (C0 stepping)
Dell Optiplex 755 (all form factors)Q35 / ICH9DOat least 1333At least 95WQ9650 Supports all 3xxx series Xeons (within FSB and TDP limits). The 5xxx series is incompatible.

Worked: X3363 (E0), X3323

Didn't work: E5440

Notes:
  • Need to reset BIOS through jumper on motherboard
Dell Optiplex 760Q43 / ICH10At least 1333At least 95WQ9650, E8600 (no 65nm support) Should support all 45nm 3xxx series Xeons (within FSB and TDP limits). The 5xxx series isn't supported, and 65nm Xeons probably aren't supported.

Not tested yet
Dell Optiplex 780 (all form factors except USFF)Q45 / ICH10DOat least 1333At least 95WQ9650 All 3xxx series Xeons (within FSB and TDP limits). The 5xxx series is incompatible.

Worked: X3363
Dell Precision T3400X38at least 1333At least 130WQ9650, QX9650 All 3xxx series Xeons (within FSB and TDP limits). The 5xxx series is incompatible.

Worked: X3363
Dell Studio 540 (M017g motherboard)G45At least 133395WQ9650, Q6700, Q6600 (95w G0 stepping only) Should support all Xeons (within FSB and TDP limits)

Not tested yet
Dell Vostro 200 (with G33M02 motherboard)G33At least 1333At least 80WDual core only At least 65nm dual core

Worked: 5160
Dell Vostro 220 & 220s (with G45M03 motherboard)G45At least 1333At least 120WProbably Q9650 All (within FSB and TDP limits)

Worked: X5450, X5365, E5450
Dell Vostro 230G41At least 1333At least 120WProbably Q9650 All (within FSB and TDP limits)

Worked: X5450
Dell Vostro 400 (with G33M03 motherboard)G33 / ICH91333At least 120WQ9650 All (within FSB and TDP limits)

Worked: X5470
Dell XPS 720nForce 680i SLIAt least 1333At least 130WAt least Q6600, QX6800 Should support all 65nm quad core Xeons.

Worked: X5365

Didn't work: X5470 (45nm)
DFI LANPARTY JR GF9400-T2RSGeForce 94001333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: X5460
DFI LP UT P35-T2RP35At least 1333At least 130WQ9550, QX9650, Q6700 All (within FSB limits)

Not tested yet
DFI P45-T2RSP45 / ICH10R1333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: X5460
ECS G31T-M7G31 / ICH7At least 1333At least 95WQ9650, Q6700, E8600, E6850 All (within FSB and TDP limits)

Not tested yet
ECS G41T-M12G41 / ICH71333At least 95WQ9650 (no Q6600 support) Should support all Xeons (within FSB and TDP limits)

Not tested yet
ECS P4M800Pro-M (v2.0)VIA P4M800Pro / VIA VT8237R+1066 (officially)At least 95WOfficially only 65nm dual core See notes

Worked: E5450 (C0)

Notes:
  • Add latest Xeon microcode to BIOS to enable 1333 FSB, 45nm, and quad core support
eMachines EL1830nForce 630iat least 1066At least 50W? Probably supports all 50W and lower 65nm Xeons.

Worked: L5320
EVGA 730inForce 730i1333At least 80W? At least 65nm dual core Xeons (within FSB and TDP limits). Not sure about quad core.

Worked: 5160
EVGA 750i FTWnForce 750i SLI / nForce 4301333At least 136WQ9650, QX9770 All (within FSB limits)

Worked: X5470, X5460
EVGA 780i SLI FTWnForce 780i1600At least 150WProbably Q9650 All

Worked: X5492
EVGA 790i FTWnForce 790i SLI1600At least 130WQ9650, QX9650 All

Worked: X5470
EVGA NF66nForce 650i Ultra1333At least 95WQ9650 All (within FSB and TDP limits)

Worked: E5450
EVGA nForce 680i SLI (122-CK-NF68)nForce 680i1333At least 120WProbably Q9650 Probably all (within FSB and TDP limits)

Worked: X5450, E5450 (E0), E5420
EVGA nForce 780i SLInForce 780i1333At least 136WQ9650, QX9770 All (within FSB limits)

Worked: X5460, X5470
Foxconn G31MG31 / ICH71333 (or 1600 when overclocked)At least 105WQ9650, Q6700, Q6600 (all steppings) All (within FSB and TDP limits)

Worked: E5450 (SLANQ)
Foxconn G31MXPG31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650 All (within FSB limits)

Not tested yet
Foxconn G41MXEG41 / ICH7133395WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: E5450 (SLBBM)
Foxconn G41MXF (rev 2.0)G41 / ICH71333At least 95WQ9650 All (within FSB and TDP limits)

Worked: E5420
Foxconn G41S-KG41 / ICH7133365WQ9550S Should support all Xeons (within FSB and TDP limits)

Not tested yet
Foxconn MCP73S01GeForce 7100 / nForce 630i1333At least 120Wprobably Q9650 Probably all (within FSB and TDP limits)

Worked: X5460 (E0)
Foxconn P35AX-SP35 / ICH91333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5405
Foxconn P43AP43 / ICH101333 (or 1600 when overclocked)At least 130WQ9550, Q6700, E8600, E6850, QX9650 All (within FSB limits)

Worked: E5160

Notes:
  • Didn't need Xeon microcode
Fujitsu D2841-A1G41At least 1333At least 80WProbably Q9650 Probably all (within FSB and TDP limits)

Worked: E5405
Fujitsu Esprimo E3521G41At least 1333At least 80WQ9550 Probably all (within FSB and TDP limits)

Worked: E5450
Gigabyte 965GM-S2G965 / ICH81066At least 130WQ6700, Q6600 (all steppings), QX6800 At least all 65nm Xeons with a 1066 FSB

Worked: L5320
Gigabyte 965P-DQ6 (rev 3.3)P965 / ICH8R1333At least 136WQ9650 (non official), QX9650 (non official) All (within FSB limits)

Worked: X5355
Gigabyte 965P-DS3 (rev 3.3)P965 / ICH81333At least 130WQ9650 (unofficial), QX9650 (unofficial) All (within FSB limits)

Worked: E5450, X5460, X5260
Gigabyte 965P-DS3P (rev 1.3 & 3.3)P965 / ICH8R1333At least 130WQ9650 (unofficial), QX9650 (unofficial) All (within FSB limits)

Worked: E5420, X5460
Gigabyte 965P-DS4 (rev 1)P965 / ICH8R1066 officially (1333 unofficially)At least 130WProbably Q9650 (unofficial), Q6700, QX6800 65nm quads (officially), but probably also 45nm quads (unofficially)

Worked: E5450 E0 (reported to work even though Q9650 isn't officially supported)
Gigabyte 965P-S3 (rev 3.3)P965 / ICH81333At least 130WQ9650 (unofficial), QX9650 (unofficial) 65nm quads (officially), but probably also 45nm quads (unofficially)

Worked: E5440 (C0), X5260 (3.33 ghz dual core)
Gigabyte E7AUM-DS2H (rev 1.0)GeForce 9400MAt least 1333At least 130WQX9650, Q9650, Q6700, E8600, E6850 All (within FSB limits)

Worked: L5410 (SLAP4)
Gigabyte EG41MF-US2HG41 / ICH71333At least 135Wq9650, QX9770 All (within FSB limits)

Worked: E5450, L5430
Gigabyte EG45M-DS2HG45 / ICH10R1333 (or 1600 when overclocked)At least 150Wq9650, QX9770 All (within FSB limits)

Worked: X5450, X5492
Gigabyte EP31-DS3LP31 / ICH71333 or 1600 (when overclocked)At least 135Wq9650, QX9770 All (within FSB limits)

Worked: E5450
Gigabyte EP35-DS3P35 / ICH91333 (or 1600 when overclocked)At least 135WQ9650, QX9770 (with overclock) All (within FSB limits)

Worked: E5450 (E0 stepping)
Gigabyte EP35-DS3LP35 / ICH91333 or 1600 (when overclocked)At least 135Wq9650, QX9770 (with overclock) All (within FSB limits)

Worked: E5450 (SLBBM)
Gigabyte EP35C-DS3RP35 / ICH9R1333 (or 1600 when overclocked)At least 136Wq9650, QX9770 (with overclock) All (within FSB limits)

Worked: E5450
Gigabyte EP41-UD3L (rev 1)G41 / ICH71333 (or 1600 when overclocked)At least 136WQ9650, QX9770 Should support all Xeons (within FSB limits)

Not tested yet
Gigabyte EP41T-USB3G41 / ICH71333At least 130WQ9650, QX9650 All (within FSB limits)

Worked: X5450
Gigabyte EP43-DS3P43 / ICH101333 or 1600 (when overclocked)At least 135WQ9650, QX9770 All (within FSB limits)

Worked: E5450 (C0), E5440, E5430
Gigabyte EP43-DS3LP43 / ICH101333 or 1600 (when overclocked)At least 135WQ9650, QX9770 All (within FSB limits)

Worked: L5420
Gigabyte EP43-S3LP43 / ICH101333 (or 1600 when overclocked)At least 136WQ9650, QX9770 All (within FSB limits)

Worked: E5410
Gigabyte EP43-UD3LP43 / ICH101333 or 1600 (when overclocked)At least 135WQ9650, QX9770 All (within FSB limits)

Worked: X5460
Gigabyte EP43T-S3LP43 / ICH101333 or 1600 (when overclocked)At least 135WQ9650, QX9770 All (within FSB limits)

Worked: E5450
Gigabyte EP43T-UD3LP43 / ICH101333 (or 1600 when overclocked)At least 135WQ9650, QX9770 All (within FSB limits)

Worked: E5450
Gigabyte EP45-DS3P45 / ICH101600At least 135WQ9650, QX9770 All

Worked: X5470
Gigabyte EP45-DS4P45 / ICH10R1600At least 135WQ9650, QX9770 All

Worked: E5450 (E0), E5472
Gigabyte EP45-UD3LP45 / ICH101600At least 150WQ9650, QX9770 All

Worked: X5460, X5492
Gigabyte EP45-UD3LRP45 / ICH10R1600At least 136WQ9650, QX9770 Should support all Xeons

Not tested yet
Gigabyte EP45-UD3PP45 / ICH10R1600At least 150WQ9650, QX9770 All

Worked: X5492, X5470, X5460 (E0), E5450, E5440, L5240, X3353
Gigabyte EP45-UD3RP45 / ICH10R1600150WQ9650, QX9770 All

Worked: X5460, X5492, L5420
Gigabyte EP45C-DS3P45 / ICH101600At least 135WQ9650, QX9770 All

Worked: E5450
Gigabyte EP45C-DS3RP45 / ICH10R1600At least 135WQ9650, QX9770 All

Worked: E5450, L5430
Gigabyte EP45C-UD3RP45 / ICH10R1600150WQ9650, QX9770 All

Worked: X5492 (overclocked to 4 GHz)
Gigabyte EP45T-DS3RP45 / ICH10R1600At least 135WQ9650, QX9770 All

Worked: E5450, X5460
Gigabyte EP45T-EXTREMEP45 / ICH10R1600At least 136WQ9650, QX9770 Should support all Xeons

Not tested yet
Gigabyte EP45T-UD3LRP45 / ICH10R1600At least 150WQ9650, QX9770 All

Worked: X5492, E5430, X5460, L5430
Gigabyte EP45T-UD3RP45 / ICH10R1600At least 135WQ9650, QX9770 All

Worked: E5450
Gigabyte EP45T-USB3PP45 / ICH10R1600At least 136WQ9650, QX9770 All

Worked: X5470, X5460
Gigabyte EX38-DQ6X38 / ICH9R1600At least 135WQ9650, QX9770 Supports all 3xxx series Xeons (the 5xxx series is incompatible).

Worked: X3363

Didn't work: E5440
Gigabyte G31M-ES2C (rev 1)G31 / ICH71333 (or 1600 when overclocked)At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5440 (C0)
Gigabyte G31M-ES2LG31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, QX9650 All (within FSB limits)

Worked: X5460 (E0), E5450 (C0), E5405 (E0)
Gigabyte G31M-S2LG31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, QX9650 All (within FSB limits)

Worked: X5460, E5335, L5430, E5405, E5310
Gigabyte G41M-ComboG41 / ICH7133395WQ9650 Should support all Xeons (within FSB and TDP limits)

Worked: E5405
Gigabyte G41M-ES2HG41 / ICH71333At least 95WQ9650 All (within FSB and TDP limits)

Worked: E5420
Gigabyte G41M-ES2LG41 / ICH71333At least 95WQ9650, Q6700, Q6600 (95W only) All (within FSB and TDP limits)

Worked: E5450
Gigabyte G41MT-D3G41 / ICH71333At least 95WQ9650, Q6700, Q6600 (95W only) All (within FSB and TDP limits)

Worked: L5430
Gigabyte G41MT-ES2LG41 / ICH71333At least 95WQ9650, Q6700, Q6600 (95W only) All (within FSB and TDP limits)

Worked: X3353
Gigabyte G41MT-S2P (rev 1.3)G41 / ICH71333At least 95WQ9650 All (within FSB and TDP limits)

Worked: E5430
Gigabyte G41MT-S2PTG41 / ICH71333At least 120WQ9650, Q6700, E8600, E6850 All (within FSB and TDP limits)

Worked: X5460 (C0)
Gigabyte GA-73PVM-S2HGeforce 7300 / nForce 630iAt least 1333At least 130WQ9650, Q6700, E8600, E6850, QX9650 All (within FSB limits)

Worked: X3363
Gigabyte P31-DS3LP31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, QX9650 All (within FSB limits)

Worked: X5260 (3.33 ghz dual core)
Gigabyte P31-ES3GP31 / ICH71333 or 1600 (when overclocked)At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5450
Gigabyte P35-DQ6P35 / ICH9R1333 or 1600 (when overclocked)At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5450 (C0)
Gigabyte P35-DS3LP35 / ICH91333 or 1600 (when overclocked)At least 135WQ9650, QX9770 All (within FSB limits)

Worked: X5460 (C0), E5440, L5410
Gigabyte P35-DS3RP35 / ICH9R1333At least 135WQ9650, QX9770 All (within FSB limits)

Worked: E5420, E5405 (2ghz quad)
Gigabyte P35-DS4 (rev 2.1 verified, rev 1.0 should work)P35 / ICH9R1333 (or 1600 when overclocked)At least 135WQ9650, QX9770 All (within FSB limits)

Worked: L5420
Gigabyte P35-S3GP35 / ICH91333 (or 1600 when overclocked)At least 135WQ9650, QX9650, Q6700, E8600, E6850 All (within FSB and TDP limits)

Worked: E5450, E5410
Gigabyte P35C-DS3RP35 / ICH9R1333 or 1600 (when overclocked)At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5440 (E0), L5240
Gigabyte P41-ES3GG41 / ICH7133395WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: X5260 (3.33 ghz dual core)
Gigabyte P43-ES3GP43 / ICH101333 or 1600 (when overclocked)At least 135Wq9650, QX9770 All (within FSB limits)

Worked: X5460 (C0), E5430
Gigabyte P43T-ES3G (rev 1.3 verified, rev 1.0 should work)P43 / ICH101333 (or 1600 when overclocked)At least 135Wq9650, QX9770 All (within FSB limits)

Worked: E5462
Gigabyte P45T-ES3GP45 / ICH101600At least 120WQ9650, Q6700, Q6600 (95W only), E8600, E6850 All (within TDP limits)

Worked: X5460 (C0)
Gigabyte X38T-DQ6X38 / ICH9R1600At least 135WQ9650, QX9770 All 3xxx series Xeons (the 5xxx series is incompatible)

Worked: X3363
HP DX2400G33 / ICH9RAt least 1333At least 120WQ9650 All (within FSB and TDP limits)

Worked: X5450
HP IPIBL-LB (Benicia) used in HP Pavillion Media Center m8430fG33 / ICH91333At least 95Wprobably Q9650 All (within FSB and TDP limits)

Worked: L5420
HP Pavilion p6110y (Asus IP-IBL motherboard)G33At least 1333At least 95WQ9550 (C0) Probably all (within FSB and TDP limits)

Worked: E5450 (C0)

Notes:
  • Couldn't find cpu support list, so not sure if E0 stepping is supported
Intel DG31PRG31 / ICH7at least 133395WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: E5450
Intel DG33FBCG33 / ICH9DHAt least 133395WQ9650, Q6600 (95w only) Does not support 5xxx series Xeons (not sure about the 3xxx series)

Didn't work: E5450, Two X5460

Notes:
  • Didn't work for 2 different people.
  • With the X5460, the Xeons and adapter worked in another motherboard.
  • Classic Series Model
  • Supports Intel Viiv Technology
Intel DG33M04G33 / ICH91333At least 95WQ9650, Q6700 All (within FSB and TDP limits)

Worked: E5450
Intel DG33TLG33 / ICH9RAt least 1333At least 105WQ9650, Q6600 (G0 & B3 steppings) May not support 5xxx series Xeons (not sure about the 3xxx series)

Didn't work: X5450, E5450

Notes:
  • Same person tried an X5450 and E5450
  • Media Series Model
  • Supports Intel Viiv Technology
Intel DG35ECG35 / ICH8At least 1333At least 95WQ9650 Motherboard may not be compatible with this MOD.

Didn't work: X3353 (but did work in another motherboard)
Intel DG41MJG41 / ICH7At least 133365WQ9550S All (within FSB and TDP limits)

Worked: L5430
Intel DG41RQG41 / ICH7At least 133395WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: x3353
Intel DG41WVG411333At least 120WQ9650, E8600 All 45nm Xeons (within FSB and TDP limits)

Worked: X5460

Notes:
  • 65nm CPUs aren't in cpu support list.
Intel DG965SSG9651066 (1333 not supported)At least 130WOnly officially supports dual cores; Quad core reported to also work Probably all (within FSB limits)

Worked: E5310 (G0), E5320 (B3), L5408 (E0)

Notes:
  • Xeons reported to only work with old BIOS versions (up to 1577)
  • Board won't boot with newer BIOS
Intel DP35DPP35 / ICH9RAt least 1333At least 105WQ9650, Q6600 (105W) May not support 5xxx series Xeons (not sure about the 3xxx series)

Didn't work: E5450

Notes:
  • Only 1 person has tried it
  • Media Series Model
  • Supports Intel Viiv Technology
Intel DP43TFP43 / ICH10133395WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: E5450 (C0)
Intel DP45ID (AA#310)G45 / ICH10RAt least 133395WQ9650 All (within FSB and TDP limits)

Worked: E5450 (E0)
Intel DP45SGP45 / ICH10R1333 (or 1600 when overclocked)At least 130WQ9650, QX9650 All (within FSB limits)

Worked: E5450, E5440 (E0), X5470 (E0)
Intel DQ35JOEQ351333105WQ9650, Q6700, E8600, E6850 May not be compatible with this mod

Didn't work: X3363 (E0)
J & W JW-P45D2-UltraP45 / ICH10R1600At least 95WProbably Q9650 Probably all (within FSB and TDP limits)

Worked: 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)

Worked: L5420, E5205, E5110
Lenovo M58e Type: 7307-PV4G41At least 1333At least 95WAt least Q9550 (C0 stepping) All (within FSB and TDP limits)

Worked: E5450
MSI G31M (MS-7379 version 2)G31 / ICH71333At least 130WQ9650, QX9650 Should support all Xeons (within FSB and TDP limits)

Not tested yet
MSI G31M3-L V2G31 / ICH7133395WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: E5450, E5430, E3113, E5205
MSI G31TM-P21 (MSI 7529 v1.6)G31 / ICH71333 (or 1600 when overclocked)At least 120WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: X5470, E5450
MSI G31TM-P35G31 / ICH71333 (or 1600 when overclocked)At least 120WQ9650, Q6700, Q6600 (95W only), E8600, E6850 All (within FSB and TDP limits)

Worked: X5460 (C0)
MSI G41M-P23G41 / ICH7133395WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: E5450
MSI G41M-P25G41 / ICH71333At least 120WQ9650, Q6700, Q6600 (G0 only), E8600, E6850 All (within FSB and TDP limits)

Worked: E5450, X5460
MSI G41M-P33 ComboG41 / ICH71333At least 120WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: E5450, X5450
MSI G41M-P34 MS7592G41 / ICH7 / ICH7R1333At least 95W (probably 130W)Q9550 (C0); Probably these: Q9650, Q6700, E8600, E6850 Probably all (within FSB and TDP limits)

Worked: E5450 (C0)

Notes:
  • Couldn't find CPU support list, so not positive if E0 stepping is supported by default
MSI P35 NeoP35 / ICH91333 (or 1600 when overclocked)At least 130WQ9650, Q6700, E8600, E6850, QX9650 All (within FSB limits)

Worked: E5472
MSI P35 NEO2-FRP35 / ICH9R1600At least 136WQ9650, QX9770 All

Worked: E5420, L5420
MSI P35 PlatinumP35 / ICH9R1600At least 136WQ9650, QX9770 All

Worked: E5450, X5460, X5450, L5420
MSI P41T-C31 MS 7610 (rev 1.0)G41 / ICH7At least 1333At least 95WQ9650 All (within FSB and TDP limits)

Worked: E5430 (C0)
MSI P43 NeoP43 / ICH101600At least 136WQ9650, QX9770, Q6700, E8600, E6850 All

Worked: E5472
MSI P43-C51P43 / ICH101333 or 1600 (when overclocked)At least 136WQ9650, QX9770 All (within FSB limits)

Worked: E5420, L5420
MSI P45 NeoP45 / ICH101600At least 135WQ9650, QX9770 All

Worked: E5450 (C0)
MSI P45 Neo-FP45 / ICH101600At least 135WQ9650, QX9770 All

Worked: E5450 (SLBBM)
MSI P45 Neo2P45 / ICH10R1600At least 135WQ9650, QX9770 All

Worked: E5450 (C0)
MSI P45 PlatinumP45 / ICH10R1600At least 135WQ9650, QX9770 All

Worked: E5450, X5460

Notes:
  • Someone reported that they needed to add the Xeon microcode to the BIOS before the system would post.
MSI P45D3 Neo-FP45 / ICH101600At least 135WQ9650, QX9770 All

Worked: E5462
MSI P6N SLI PlatinumnForce 650i SLI1333At least 130WQ6700, Q6600 (all steppings), QX6850 Officially supports all 65nm quad core (within FSB and TDP limits); 45nm quads are not officially supported, but someone reported an X5460 worked.

Worked: X5460 (C0), E5345 (SLAEJ)
MSI P7N DiamondnForce 780i SLI / 570i SLI1333 (or 1600 when overclocked)At least 136WQ9650, QX9770, Q6700, E8600, E6850 All (within FSB limits)

Worked: E5470
Pegatron IPMEL-PRCG41 / ICH7133395WProbably Q9650 Probably all (within FSB and TDP limits)

Worked: E5405
Shuttle SG33G5G33 / ICH9DH1333At least 95WQ9650 Probably all (within FSB and TDP limits)

Not tested yet
Shuttle XPC SG41J4G41 / ICH71333At least 95WQ9650, E8600, E6850 (65nm quad core Q6700 not supported) Probably all 45nm (dual and quad) and 65nm (dual core only) Xeons (within FSB and TDP limits)

Not tested yet
XFX 680i ltnForce 680i LT SLI1333At least 130WQ6700, QX6850 65nm quads (officially), but reported to also work with 45nm quads.

Worked: E5450, X5460, X5450 (C0)

Notes:
  • 1 person reported an X5450 (C0) wouldn't boot until they flashed the P08 BIOS
XFX 780inForce 780i1333At least 120WProbably Q9650, probably QX9650 Probably all (within FSB and TDP limits)

Worked: X5460
XFX 790inForce 790i Ultra1600At least 136WQ9650, QX9770 All

Worked: X5470 (E0), E5440
XFX 9300GeForce 9300133395WQ9650, Q6600 (95W only) All (within FSB and TDP limits)

Worked: L5420
Zotac 620i (MCP73)nForce 620i1333At least 120WQ9650 All (within FSB and TDP limits)

Worked: X5460
Zotac GF9300 ITXGeForce 9300133395WQ9650, Q6700, Q6600 (G0 only) All (within FSB and TDP limits)

Worked: E5450, E5440
MotherboardChipsetMax FSBMax TDPLGA 775 CPUs SupportedLGA 771 Xeon Compatibility

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 through the jumper on your motherboard or by removing the CMOS battery

We don't recommend simply loading the default settings in the BIOS, since isn't enough in some cases. This will avoid many potential problems you may run into.

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, so you don't weaken the adhesive when you handle the adapter.

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.

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 isn't sticking securely enough, you can also use double-sided tape to secure it to the processor

The easiest way to do this is to attach the end of the adapter to a big piece of double-sided tape, and then cut around the adapter using the little scissors that some people use to cut their fingernails. Just make sure the tape only covers the ends of the adapter (so it doesn'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 - Turn on your system, go into the BIOS, and load the default settings

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

Note: Your system may cut itself on and off several times before booting up correctly the first time. 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.

And if you still need an adapter or a Xeon processor, check out the following links:

Let us know if this mod worked on a motherboard that isn't in our list

Please leave a comment with your:

  • Motherboard model number (and revision if it has one)
  • Xeon model number (and stepping if you know it)
  • (Optional) chipset, max FSB, max TDP, and supported LGA 775 processors

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.

Windows 8.1 won't install

If Windows 8.1 won't install because it says your processor is missing some functionality (like CompareExchange128), the following information should help you to get it installed.

Make sure you're running the latest BIOS

These problems are usually due to do outdated CPU microcode in the BIOS, so if you haven't tried already, make sure you're running the latest bios.

One person that already had the latest BIOS said reflashing it again fixed this problem, so you may want to try that too.

If you have the latest BIOS installed, try adding the latest LGA 771 Xeon microcode to your bios

The latest LGA 771 Xeon microcodes should contain all of the functionality Windows 8.1 needs, so we recommend adding these microcodes to your BIOS. Multiple people have successfully installed Windows 8.1 after doing this.

Full details on adding the microcodes are available: here.

Once the microcodes are updated, make sure you fully reset your BIOS (through the jumper on your motherboard or by removing the CMOS battery), and then load the default BIOS settings when you boot up for the first time.

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 (or missing functionality). It's also relevant to this problem.

My system is overheating (or running hotter than expected)

Your temperature monitoring program may be telling you the wrong temp

Some temperature monitoring programs don't report the correct temperature for Xeon processors, so your CPU may not be running as hot as you think. The reason this happens is they're using the wrong tjmax value, which is used to calculate the current temp.

AIDA64 should read the correct temperature by default (the temps are under Computer -> Sensor). However, you can also manually set the tjmax in many monitoring programs, which should make them also report the correct values.

You may need a better heatsink and fan

Intel usually gives smaller heatsinks for their dual core processors, so if you were previously using one of those and upgraded to a quad core Xeon, you may need to upgrade to a better heatsink. It all really depends on your previous processor's TDP and the new TDP.

However, before buying a new heatsink, you should try the solutions mentioned in the next section: My system will boot up, but my Xeon is not working as expected (or is missing functionality). Specifically, adding the Xeon microcode could also help with overheating.

My system will boot up, but my Xeon is not working as expected (or is missing functionality)

This section should help if:

  • Your processor is missing functionality (like Speedstep, SSE 4.1, VT-X, or CompareExchange128)
  • Your system is very slow and doesn't seem to be running at full speed
  • Your system is crashing, freezing, rebooting, or not working as expected

Things you should try:

Try loading the default settings in your BIOS

If your system boots up fine, but it's not working as expected, the first thing you should try is to go into your bios and load the default settings.

Try resetting your BIOS (through the jumper on the motherboard or by removing the CMOS battery)

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 latest LGA 771 Xeon microcode to your bios

If resetting your bios doesn't help, then you should try a bios mod. A bios mod will add the latest LGA 771 Xeon microcode to your bios (instead of using the similar LGA 775 microcode which may not be current enough). This should fix most problems (including missing functionality).

How to add the LGA 771 microcode to your bios

If you have an Award, AMI, or Phoenix bios, you can add the LGA 771 Xeon microcode yourself by reading these tutorials:

If you have a different type of BIOS, you can also request a bios mod at overclock.net.

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 and stepping for your old LGA 775 processor (so they can make sure they leave the microcode for that processor)

If your system still seems very slow, try disabling the power saving features in your BIOS

The power saving features like speedstep and c-states (C1E and others) may not be working correctly with your motherboard, and it could be causing your processor to run at its minimum speed. You should try disabling them to see if it helps.

You can test what speed your CPU is running at with CPU-Z. It should run at full speed if you run something stressful like a benchmark or AIDA64′s system stability test.

If your system still crashes, freezes, or is unstable, try increasing the CPU voltage

If you're still having stability problems at this point, your Xeon may no longer be stable at its stock frequency and voltage. This can happen over time as all processors eventually degrade with use.

I recommend increasing the CPU voltage in the BIOS. This may make your system more stable. If you aren't able to alter the voltage (or don't want to), try decreasing the CPU multiplier or reducing the FSB speed. This will run the processor at a slower speed, which may make it more stable.

If that doesn't help, you may need to adjust other voltages or speeds related to the chipset, FSB, or ram. If you're not familiar with how to do this, I recommend searching for a core 2 quad overclocking guide. Even though you're not overclocking, it should cover what to adjust to get your system stable.

And if none of that helped, try reinstalling Windows

This has helped for multiple people that were having problems like rebooting, BSODs, 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 (through the jumper on the motherboard or by removing the CMOS battery)

This should fully reset your bios and any of the information it's stored about your old processor.

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

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 works with your old processor, your system probably wasn't damaged during the mod. However, we have heard of two cases where a socket pin was bent or broken, which caused the Xeon processor to not work, but the old LGA 775 processor still did. So, you should definitely check for broken pins.

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.

284 comments

Leave a reply
  1. Jason Nutt

    Works great with HP DX2400 and Intel® Xeon® Processor E5440
    (12M Cache, 2.83 GHz, 1333 MHz FSB) Got a bios mod with latest microcodes from Overclockers, PS be careful not to bend pins it cost me an extra hour!

  2. Richard

    Works great on HP/Asus IPIBL-IB motherboard. Used in HP DX2400 and HP Elite Pavilion M94245F (among others). Needed to get a bios mod with the latest microcodes from Overclockers. Using Xeon E5450 Quad 3.0Ghz with no problems.

  3. genpix

    Noticed that the table does not have any info about MBs with 3210 chipset. Want to fill some gap.
    I tried X3363 on a Supermicro X7SBE motherboard (it’s a server grade MB, with several PCI-X slots, ECC SDRAM, http://www.supermicro.com/products/motherboard/Xeon3000/3210/X7SBE.cfm), which uses Intel 3210 chipset + ICH9R. Even though this board has a Phoenix BIOS, neither of utilities can edit it (cbrom195 simply hangs). BIOS does not have any CPU adjustments though (Vcore voltage, FSB frequency, etc.). Everything is at default settings, and X3363 works just fine (left IntelBurnTest to run for several hours, no problems at all). Have to mention though: CPU-Z can not pull all the info from this system correctly: (1) in the main tab (CPU) it calls this CPU as E5440, but few lines lower (Specification) it lists it correctly, X3363; (2) core voltage is “frozen” at 0.096V, it does not go up or down with change in CPU load/multiplier (I guess, CPU-z can not read the real voltage and simply lists the nominal average voltage for this CPU); (3) Memory tab is not populated (CPU-z can not read any of the current memory settings), though, SPD parameters for all modes (next tab) are read correctly.

  4. genpix

    forgot to mention: This X3363 is C0 stepping (SLASC).

  5. Dan

    intel Xeon L5420 (E0) and ASUS P5K working fine ;). But BIOS must have updated microcode to remove message for incompatible processor.

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