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 $35 (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. Fouzan

    My current setup is a ASUS P5B-E Plus and have the latest bios 0638. I have a Xeon X5492 and it is stated to be compatible with my motherboard (as compared to the other P5B series, correct me if I’m wrong). I’ve modded the BIOS to 067A with the 44 binary file to support the Xeon but the CPUID states that it is actually 067Ah (with an h)… could this be an issue? Powers up no post but still works with my older Core 2 6600. Trying to investigate with the other issues (one ram stick, reset bios, sticker, tabs) but still no result…

    • syn Moderator

      The specs for your motherboard list a 1066 FSB as the max supported without overclocking, so that may be the problem. The X5492 is a 1600 FSB CPU.

      The CPU support list of your motherboard does list support for some 1333 FSB CPUs, but it says “Due to chipset limitation, 1333FSB processors can only run at a maximum speed of 1066FSB on this motherboard.” That means those processors would also run at a slower speed due to the lower FSB.

      The h at the end of the CPUID just means it’s a hexadecimal number, so the h isn’t actually part of the CPUID.

      It sounds like you’ve tried most of the stuff I’d recommend, so it’s also possible you have a bad adapter or a defective Xeon (less likely) if the FSB isn’t the problem.

    • Sklivanitis Dimitrios

      It will not work what ever you do, 1600 processor will not work in 1066 motherboard, not even in 1333. My MSI p35 platinum with 1333 fsb works great with xeon 5470 at 3,33 MHz cause it runs at 1333.

  2. Warren

    Asus P5W-DH-Deluxe with X5450(E0) was able to post and boot, but ran very unstable. Upped the Vcore to 1.35 and it ran a little more stable, but still some issues. The bios update with modified microcode failed and caused the system to no longer post, I have a new bio chip coming in this weekend and will test a bit more.

  3. brice

    HI, i have a ecs g41t m6 motherboard and replaced my intel e7500 cpu with a modded xeon e5450. The problem i have is that it takes around 10 mins to boot up now and everything is slow. I have tried resetting the bios. I checked my cpu temperature is around 50 – 60 degress.

  4. Brice

    HI, i have a ECS g41t m6 motherboard and i just i replaced my intel e7500 cpu with a modded intel xeon e5450. My boot up time takes around 20 min and everything becomes really slow. I have already reset my bios.

  5. Dmitry

    Hi everybody! I`ve ASUS P5E-VM DO Data from tabel: “Q35 1333 ≥ 130
    Q9650, QX9650, Q6700, E8600, E6850 All
    Worked: E5410 (E0)

    5xxx series Xeon worked even though the chipset was Q35
    ASUS motherboards with a Qxx chipset may not have the 5xxx series incompatibility problem”

    Tell me, please: will proc. Xeon X5460 work with my MB? I need answer YES or NOT, without MAYBE. I want to buy X5460 in another city of Ukraine through Inernet, so don`t want to loose money. Thank a lot for any advice.

  6. zstandig


    I’m reporting that this totally worked on my HP xw4600.

    Went from a Core2 Quad to a Xeon,

    I got a E5440, 45nm. It’s about the same frequency as my Core2 it replaced, and has the same FSB. The prime reasons for the upgrade other than the cool factor had to do with more cache and SSE4.1, VT-X.

    Putting the sticker on the CPU was tricky, I needed to use forceps and a magnifying glass under bright lamp to get it lined up right. It all worked out though. Cutting the socket was slightly more difficult than I anticipated, but I managed to do it with a pocket knife. I then popped out the CMOS battery for a bit in order to reset the BIOS.

    I had to go through the settings, re-enable a few things, switch to ACPI, than everything booted back to Windows just fine. It complained about a micro-code update, problem is the micro code I have is newer than the latest that HP provides for this machine. So I have to press F1 to boot the computer. But all in all I’m happy it worked out.

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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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