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 $15 (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

1,808 Responses

  • arisma September 18, 20172:15 pm

    Gigabyte GA-965P-DS4 rev 2.0, Xeon E5450 E0 SLBBM
    I have inserted microcode for it(1067A, platform 44).
    Motherboard already have 1067A but platform 11(775) so it runs with failures.

    After flashing nodded bios all went great.


  • kaastrup September 18, 20175:39 pm

    After trying to do a “771-MOD (Xeon)” on this old MB and updating the BIOS, the board does not power on anymore. I have a green light on the motherboard but when I am pushing the power button the PSU and CPU-FAN is staring for 2 sec. but then stops again. If I keep pushing the power button the PSU and CPU-FAN keeps starting for 2 sec at a time, but I never get anything on my monitor and no POST or BEEP.
    My question is – would a new bios chip repair this fault, or is it the CPU pins or board itself which is faulty ????

    • Stepa September 20, 20177:03 pm

      The motherboard stopped turning on after the CPU replacement or after the BIOS update?

      • kaastrup September 21, 20174:28 am

        Hi – Its a while ago I did it, but I think the motherboard stopped working after the BIOS microcode update, when I booted, but then of course I already had the X5472 (with modding) sitting in the socket.
        If the sticker for the mod was not sitting right on the pins on the back of the CPU, could that somehow short circuit the mortherboard ????
        I am pretty sure I remember that the mortherboard was booting up with a fault after POST, but I was able to go into the BIOS, but then something else happend, but can not remember what exactly :-(…..

        • kaastrup September 21, 20174:29 am

          I forgot to mention Its a ASUS P5QC mobo

  • krists September 20, 20178:07 am

    mobo ga-p35-s3g
    cpu x5450. worked without microcodes. but i have random crashes. i dont know if psu or gpu is faulty. or maybe just need update microde.

    • Stepa September 20, 20176:59 pm

      To find out what the problem is, the easiest way to add a microcodes.

  • sparky1442 September 21, 201712:45 pm

    im doing this on a acer g33t-am with an x5450 processor is this config possible can you guide me throgh this process


Leave a Comment

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.