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 eBay 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 $6 on eBay (usually much 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

2,293 Responses

  • Marcus Brown August 30, 20185:59 pm

    Gigabyte GA-EP35-DS3R update: X5450 didn’t work! PC refused to POST.

  • Marcus Brown September 2, 201812:07 pm

    I’ve been looking into the HP 3120 fast fan isue a bit more. On Bios Mods i found this thread discussing same issue, same IPIEL-LA3 mobo:


    Their efforts don’t seem to have been successful.
    The Insyde bios’s that HP uses are discussed in detail on Donocvan6000’s blog. the direct links to his blog here on delidded don’t seem to work, I have found his tutorials on web.archive.org


    Basically its a lot more work and risk getting into and modding these bios that are wrapped up in exe.
    Browsing the comments here suggests that one can also run into issues installing win 10.
    I think I will just use a core-2 quad in the box I intend to move on….

  • Marcus Brown September 2, 201812:37 pm

    correction/clarification the bios on my HP 3120 APIEL-LA3 board is an American Megatrends (v 6.07)

  • Marcus Brown September 3, 20186:36 pm

    Success with APIEL-LA3 … I think….

    The bios comes in an exe package containing UCORESYS.SYS, UCOREVXD, UCOREW64.SYS, afuwin.exe, a .cva file, flash.bat and a vxd file. I extracted this using 7-zip to add this cpuid = 1067a microcode
    to the main bios file EU36.07, which I had to temporarily rename to .rom, using mmtool (following the tutorial here on delidded.com).
    I then created a DOS bootable usb drive, put on the modded bios and AMI flash tool AFUDOS.exe. Although the BIOS setup doesn’t have usb listed as a boot device, in practice once the usb is plugged in it is detected and pressing ESC on boot goes to a boot choice screen where the USB is listed.
    The command
    AFUDOS.exe /p /b /c /n /x
    (see: http://www.ecs.com.tw/extra/flashutl/afuusb.pdf )
    then flashed the bios successfully.
    Reboot success into windows 7. Fan nice and quiet! Things seemed a bit slow initially, however CPU-Z reported the cpu running correctly at 3GHz, and a test using adobe DNG converter gave same results as before for conversion of a folder full of pics – 9 secs.
    Date however had reverted to 2002.

    • Marcus Brown September 5, 20186:26 pm

      Spoke too soon. System runs slow. Booting issues :(

  • Asakura Shinji September 8, 20185:09 pm

    ACER or eMachines EL1850 Motherboard G41T-AD tested in Xeon X5450
    Problem founded:
    1. The DDR3 RAM will no longer able to supports in 4GB only 1GB or 2GB, but the original LGA775(eg. Pentium E5700) will work fine
    2. All OS bootup time will be 10 times longer tested in Liteon 128GB SSD (Windows 10 used around 600 Sec, Ubuntu 300 Sec)
    3. But Game Performance works fine after bootup
    4. Single Core Performance very poor compared with other G41 Motherboard

    Conclude: Usable but very buggy

  • envoycdx September 9, 20184:26 am

    ASRock G31M-S

    Running with stock BIOS 1.60, no modding / injection of the micro-code.
    Xeon E5462 CPU (running @ 1600FSB)

  • roog September 9, 20182:26 pm

    What about the Xeon CPUs that have been modified to fit a 775 socket? Does anyone have experience with those?

    • roog September 13, 201811:52 am

      I can answer my own question by saying that I installed a Xeon X5460 (which had already been modified to fit the LGA 775 socket) on an ASUS P5Q-SE2 and it is running fine with 8GB of memory. The BIOS is currently version 0801 and on boot I get the message that I should upgrade the BIOS to take full advantage of the processors capabilities. I have not tried any overclocking.

  • Al September 11, 20183:13 pm

    Work fine Xeon mod on asus P5QL PRO following your guide, but i cant increasd the ram when i mounting the other module pc dont boot . Please help emailing me

  • arevalosk5 September 16, 201811:02 am

    Alguien me echa una ayudita por favor? pues necesito que alguien me diga de como instalar los microcodes de 771 a 775, yo tengo una placa madre G41D3C Ver.7x DDR3, y e encargado un procesador Intel XEON E5450. Y quisiera saber si es compatible, mi procesador actual es un DUAL CORE E5700. E visto por alli que mi placa madre es de 95 w, y el xeon que pido es 80 sera que es compatible, supongamos que si pero algunos le sale el TDP sobrepasa el limit presione F10 como haría para quitar ese error y el sistema inicie correctamente, SI ALGUIEN ME AYUDA A TODOS ESOS ERRORES YO LE DONO A PAYPAL 10$

    • arevalosk5 September 16, 201811:03 am

      Can someone help me please? I need someone to tell me how to install the microcodes from 771 to 775, I have a motherboard G41D3C Ver.7x DDR3, and e commissioned an Intel XEON E5450 processor. And I would like to know if it is compatible, my current processor is a DUAL CORE E5700. And seen there that my motherboard is 95 w, and the xeon that I ask is 80 will be compatible, suppose if but some TDP exceeds the limit press F10 as you would to remove that error and the system starts correctly , IF SOMEONE HELP ME ALL THOSE ERRORS I GIVE YOU A PAYPAL 10 $

  • Alessandro September 16, 20184:15 pm

    I need a motherboard ddr3 cost vs benefit for the x5470, any recommendations?


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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.