LGA 771 to 775 Adapter (MOD) – Run faster 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 faster (and usually cheaper) Intel Xeon processors (LGA 771) into a 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.

List of LGA 771 & 775 CPUs + Current Prices

The pages shown below should help with comparing Xeon prices and specifications. The first link has all the LGA 771 and LGA 775 CPUs combined into 1 table (sorted by price), and the others are the original uncombined pages.

Where can I get an adapter?

Here's a current list of sellers (sorted by price). The sellers are located all over the world, so you should be able to find one that's close to you, and most of them will also ship worldwide.

Why would you want to do this?

Xeons are usually MUCH cheaper

For example, the Xeon E5450 is equivalent to a 3.0 GHz Core 2 Quad Q9650, and it currently costs about $25 (about $70 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 switches two of the pads 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


Leave a reply
  1. Krishna Kumar G

    I wish to install Xeon E5450 on my Board

    Boistar G31M+ Ver. 6.x
    Intel G31 / Intel ICH7
    Maximum CPU TDP (Thermal Design Power) : 95Watt

    May I know weather its compatible or not Please help

  2. P43Twins1600 with E5462


    I thought that Asrock P43Twins1600 + Xeon E5462 (SLANT) works 100% properly, but there are some issues.
    Maybe my mobo is faulty or something, but when working in full FSB 1600MHz there are problems with RAM causing BSOD’s and crashes from time to time. Memtest shows many errors, every single DDR2 stick checked and it was the same. Higher voltages didn’t help…

    But I found solution. I had to lower FSB using MANUAL oc mode in bios and now my Xeon E5462 works with 2670Mhz (instead of stock 2800Mhz).
    vCore – 1.225
    VTT – High
    NB – Middle
    PLL – Low

    It’s stable now, no Memtest errors, passes Prime tests on all cores. PassMark CPU test shows 4096 (stock 2800Mhz – 4133). Later I found on some forums that there are problem with some cpu’s and motherboards using FSB 1600, so it’s safer to go with FSB 1333 cpu’s. Hope it helps someone.

  3. Looftie

    Xeon E5440 (E0 stepping) works fine on an Intel DP43TF motherboard (P43, ICH10, 1333)

    As another Intel motherboard user mentioned, the system won’t boot on a restart or reset but it does boot normally if you shutdown first.

  4. mathmosme

    The MSI G31M3(MS-7528) is working fine and stable with a E5450.
    rem: you sould not need the OEM Logo.

  5. 1Yakka

    E5450 E0 worked on an MSI P965 Platinum (P965) but only with a Beta version of the bios A7238IMS.193 (V19 Beta 3)
    This mobo is not in the tested motherboard list, please add it!


  6. ToYo94

    Motherboard: Biostar G41D3C
    CPU: Intel Xeon E5450 SLBBM E0
    OS: Windows 10 Pro 64bit
    When I installed CPU and powered computer, first thing it displayed was “The MAX TDP of cpu is over 95w, prepare to shut down in 10 seconds”
    This can be skipped by pressing F10 every time you turn on computer.
    Then I went into BIOS and saw it recognized the CPU. But after booting into Windows, it was saying I still had the old CPU, and CPU-Z didn’t show new instruction sets SSE4 and 4.1.
    So as said here, I tried resetting CMOS and default settings in BIOS. But after that I was always getting stuck at Windows logo, it didn’t want to boot. I tried changing SATA/IDE configuration in BIOS, tried inserting USB with recovery drive, and none of it helped. Finally, I downloaded the BIOS and inserted microcodes on another PC, and flashed them VIA USB. And it finally booted into Windows, recognizing CPU, and new instruction sets.

    So for users with this motherboard, make sure you updated BIOS with microcodes before changing your CPU!!!

    Still don’t know how to remove the annoying message at boot about CPU being over 95W TDP, which it isn’t.

    • Pedro Alonzo

      I have same motherboard, and i have the same problem, bios update don´t remove this problem, i tested Xeon E5440

  7. Yura

    MotherBoard: P5KPL-E
    CPU: E5450
    Works fine.

    So I’ve replaced my E8200 in Asus P5KPL-E motherboard. Memory 4x1GB-800-dual.
    Tried without bios updating (latest 0601) it was started but with lack of features, no speed step, vt-x somehow identified but wasn’t workable. Did some tests, stable, almost all benches shows twice performance growth sure 2 cores vs 4. Memory worked with the same performance. But sure CPU was little bit “hot” – 50C with my old zalman in quiet mode. So this CPU able to work without bios update. Aida is not able to identify temperatures and memory mode. IPDT2 – failed i don’t know reason. But CPU-z, aida tests are successful.

    To get full advantages you need to update BIOS and very important to perform CMOS clear.
    After updating you’ll get additional options: EC1, VT-X, PECI, Speedstep.
    DO NOT ENABLE C-STATES (c2,c3,c4) – you will experience slow system, suppose it will happen for any motherboard.
    IPDT2 – success stable – start temp below max – “E8200-56C, E5420-56C”, end temp – “E8200-55C, E5420-46C”, not sure what value is max maybe 100C.
    IPDT3 – fails with reading temperature service error, maybe bug in IPDT3.
    AIDA -doesn’t read temp and memory settings, looks like aida problem. Memory test after BIOS update shows little bit less performance, but it’s make no difference. All CPU tests shows better performance after bios update.
    CPU-z – success stable – shows memory settings and temperatures fine.
    Linux – everything fine, shows all temperatures without problem, few benchmarks were stable.

Leave a Reply

Problem with this MOD? Please read the troubleshooting section before reporting a problem. If that doesn't help, please tell us all of the things you've already tried.

Unsure about compatibility? Please read the motherboard compatibility and tested motherboards sections of this guide.


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