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

2,386 Responses

  • Marco March 15, 20194:57 pm

    Hi, i have an ASUS P5QD Turbo and a xeon e5450: PC boot up till Windows logo, then it freeze and shuts down; any solutions?

    • Everton March 20, 201912:59 pm

      Same here

      • Marco August 1, 20197:48 am

        hi, have you found any solution?

  • Fourfree March 15, 20197:10 pm

    Hi all

    Trying to use a Asrock G41C-VS motherboard with bios mod. Having no luck with a E5462 and X5460 cpu. Both cpus work in my Gigabyte GA-G31M-ES2L with mod. Can not find much info with this motherboard. Has anyone good any working info of Asrock G41C-VS.

    Any information welcome.

    • Fourfree May 15, 20195:00 pm

      Update Asrock G41C-VS now running on

      CPU Name
      Intel® Xeon® CPU E5450 @ 3.00GHz
      1 CPU – 4 Core – 4 Threads
      3004.13 MHz (9 * 333.79 MHz)
      Current: 9 / Min: 6 / Max: 9
      Harpertown / Stepping: C0 / Technology: 45 nm
      CPUID / Ext.
      6.7.6 / 6.17
      IA Extensions
      MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, EM64T, VT-x
      L1D : 32 KB / L2 : 6144 KB
      Caches Assoc.
      L1D : 8-way / L2 : 24-way
      Rev. 0x60F
      1.128 Volts
      57 °C / 135 °F
      Retail (Stock Frequency : 3000 MHz)
      Cores Frequencies
      #00: 3004.13 MHz  #01: 3004.13 MHz  #02: 3004.13 MHz  #03: 3004.13 MHz

  • Marco March 19, 20196:42 am

    Hello everyone,

    Is the Gigabyte GA-73PVM-S2H motherboard (rev. 1.0 with F9F BIOS) compatible with the Xeon E5405 CPU ?

    Thank you for your help.

  • Havsfrun March 28, 201911:52 am

    Installed L5420 into my ECS P45T-A
    Bios Version: 080015, Release Date: 05/20/2009.
    System boots without any modifications.

  • ASrock G-41M-S March 31, 201910:24 am

    Здравствуйте! У меня материнка ASrock G-41M-S ,какой подойдет проц?

  • Armand March 31, 20192:08 pm

    I have tested Xeon 3.16GHz X5460 C0 stepping , with Asus P5K SE mobo , for almost one week. The X5460 has passed Intel Diagnostic Tools and Tests. However, Asus motherboard still needs the xeon microcodes, otherwise I have to press F1 to resume and continue the booting process. Recently after searching the bios microcode’s mod how to , I got the modified P5K SE bios mod from overclocker.net . The bios is working fine, no problems. I flashes the bios and it works flawlessly.

    However , the only ON GOING problems I still experience, the computer sometimes is very difficult to turn on ….. scenario #1 : After I press the power on button, the computer turn on for 1 second, and then shut off abruptly , and 1 second later , the computer turn on back again and continue windows 8.1 booting process. Scenario #2 : the computer turn on for 1 second , and the shut off abruptly and stay dead until I turn off the master power switch behind the psu for few seconds , and I restart the process again .

    Anyone have solution(s) to overcome the problems ?

    Bios reset , checked
    Latest Bios with Xeon microcodes, checked
    PSU is 650 watts with dedicated three 12v rails . I am very sure my power supply is more than enough.
    Windows 8.1 , checked , no problems.
    Intel Diagnostic Tools and Tests , checked , all passed .
    CPU temperature 72C , open casing .
    CPU voltage , Auto , 1.140V
    FSB Overclock , 360 mhz x 4 = 1440
    CPU Overclock , 360 mhz x 9.5 = 3420

    • travma June 28, 20191:04 pm

      The electrolytic capacitors maybe bad, memory dimms are defective or the RAM slot aren’t communicate well with the DIMM because of the defective capacitors on the motherboard. Also check the problem with different GPU card and don’t overclock. I bet that this is capacitor problem. Test it with only one DIMM RAM to spot the defective slot.

  • SteppoBlader April 2, 20194:09 pm

    Hi there! I’ve recently bought an Asus p5k64 ws mobo to use with a xeon x5470. No matter how hard I tried it did not work. I followed the turorial from beginning to end. The rig goes on and off continuously in an everlasting loop. I have injected the x5470 microcode into the latest bios, tested all the preinjected bios I cud find still to no vail. Follow the procedure to the letter from flashing the bios to reset the cmos, tried reseating the cpu, replacing the sticker, switching ram sticks, currently running 2 samsung 4gb ddr3. When I go and use a q9550 from the other rig it works flawlessy. Even if on this page ia stated that the mobo is fully compatible with such cpu mine just it is not. Any help will be greatly appreciated. Best regards

  • SPIKE April 8, 201911:15 pm

    I have a Gigabyte mobo GA-EP45T-UD3R I went to the site downloaded bios for the mobo but its a .F2 File how can i get it to be a .ROM I tried to rename it like this site said to do nope didn’t work.

    Any help would be great thank you (-_-)

  • soteris April 10, 20192:30 am

    MSI G31M3-F Intel® G31 Chipset Supports FSB 800/1066/1333 MHz
    worked with E5440 1067A SLBBM
    bios version 1.3

  • ECS 965t-a rev 1.0 April 22, 201912:52 am

    Здравствуйте эта материнка не где не указанна. искал под нее биос, пишут что 965 чипсет тержит зеоны 4 ядерные а биоса нет модифицированного, помогите пожалуйста


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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.