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 $30 (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. Peter Dagger

    Hey, i got an E5450 for my Asus p5b-e mobo.

    I modded latest 1807 bios release using both 44 and 11 platform bin files for 1067A and deleted the old one.

    I used asus upgrade utility to flash it and i got my bios corrupted… got error when it was verifying (last step).

    I rolled back to an earlier bios version and i am using my old cpu.. but i am a bit afraid now to move on, so i want your kind help.

    What am i doing wrong guys?

    • mesa57

      First try without upgrading you’re bios.

  2. Stefan

    Gigabyte G41m-combo rev 2.0 working with E5430 EO all instructions works after modded bios.


    DFI Lan Party Dark T2RS (P35), updated to latest available bios on DFI website (which adds support gor Intel Q9xxx CPUs), worked right away with Xeon X5460, cooled with the stock Intel heatsink for the Q6600, the one double the size and copper core, the Intel D60188-001.

  4. Tom

    Foxconn P35A-S, XEON X4560.
    Working now, with updated BIOS. Didn’t start with the old one, had to update to the 2009 one.

  5. Frank

    – Asus P5G41T-MLX
    – Xeon E5450 SLBBM
    – Microcodes and BIOS Update required!
    – 1333 FSB auto detected

    Working perfect!

  6. CroMagnaTron

    Asus P5KC – Working fine with X5450 – Booted fine, but I modified the BIOS for all versions of Xeons to work, and I am Overclocking it at 3898 – 3.8Ghz official seems to be fine with a 1.4V. Going to step back down after I see if I can get this over 4Ghz…

  7. Mike

    I’ve had success with the Xeon E5450 and a P6N SLI Platinum motherboard BIOS rev 1.7. I did have to go into the BIOS and link the memory speed with the CPU. So far everything is stable. I ran Prime95 for 24hrs with flying colors. :)

  8. ali

    I could not make my xeon e5450 (slanq) work for my pegatron 2a94h board, i made the update with microcodes but my pc worked to slow, now i bought a MSI P45 Neo-F , will my cpu work with my new board well, i checked the test result of your site i saw the results ok with xeon e 5450 (Slbbm) not with slanq, is there big different between that two cpus, thanks for your understand …

  9. narith

    can someone help me update my microcode for a dell optiplex 780

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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.


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