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

2,484 Responses

  • Spart January 18, 202110:56 am

    Just an update.

    P5Q3 Wifi Deluxe
    Xeon L5430

    I had been running an L5430 for a long time. Very Stable was running with DDR3 1333.

    Just upgraded it to a E5472 with DDR3 1600 overclocked to 3.33Mhz. Very stable and working fine.

    FSB 444 7.5x

    Not sure how I get the ram to overclock to 1600 if anyone knows on this MB please post.


  • Richard January 19, 20212:11 pm

    Hi i just put a xeon e5462 2.8ghz in my msi g41-p26 motherboard and it booted up and is working but the cpu speed in bios and cpu-z in 2.33ghz even under load. Also task manager shows that the speed is around 2.7ghz even though cpu-z shows 2333mhz at the same time.

  • Richard January 22, 20213:45 am

    Dell DG33M03 mobo: failed multiple times until I replaced the sticker. Now running happily with an x5470

  • Trudi Morrison-Gardiner January 24, 20218:50 pm

    Is it possible using an E5345 in this method? We a couple spare from a server strip down, intending to use in a surveillance system we built. 🙂

  • Frank February 1, 20213:55 pm

    Please can someone help me, I have a ms 7284 g945 motherboard with bios locked..it doesn’t let me read dual cores either!
    How can I change the bios?

  • Casey February 9, 20214:35 pm

    I installed an E5450 in a Acer prebuilt system. It had an E5500 originally installed. It posts to the bios and shows the E5450 properly but it isn’t working properly. I have spent countless hours working on this. The main issue is windows won’t load consistently. Every time this happens I need to reinstall the E5500 in order to boot properly. I have installed the latest bios directly from Acer but that was already installed. I have installed all three 771 microcodes at once and that didn’t help. I then installed one of the 771 microcodes at a time. With the one with 40 in the platform section installed I was able to boot into windows. Unfortunately it wasn’t working properly. It only showed 2 cores in task manager and HWMonitor. In CPUID it did show that the E5450 was installed and running at 3.0 ghz but nothing else showed that. After rebooting a few times the same issue started again. It posts and then the windows logo appears and it then reboots. That cycle will continue until I power it down.

    I have tried everything I can think of but nothing has worked. It seems like a bios/microcode issue to me. I know trying this mod with a prebuilt system was risky because I can’t do much in the bios. Any ideas of what I can try next or should I just give up and buy a 4 core 775 cpu to replace the E5500?

    • David February 21, 20219:24 am

      Casey February 9, 20214:35 pm
      When you boot windows with 2 cores instead of 4 is just simply windows setting to get it working:
      msconfig/boot/advanced options/ number of procesors (set 2) and restart. Thats all.
      msconfig = system configuration tab

  • Kevin D February 9, 20216:09 pm

    Good evening, I bought on EBAY a XEON x5492 compatible LGA775. I installed it like on the tutorial but it doesn’t work. I put a bigger power supply (400 watts). I put the factory settings back in the bios. And when I turn on my black screen machine and after a few minutes it turns off. The model of my motherboard is a Veriton M275 and a G41. In the tutorial it says that all G41’s are compatible. What can I do?

  • RelaxingTimes101 February 13, 20213:46 pm

    hi guys do you know if a xeon L5420 can works in my biostar g31d-m7? because i know my mobo have tdp up to 65w.

    and I also need a modded bios with microcodes if anyone already has it please pass it to me rdcmr101@gmail.com

  • Spencer February 22, 20215:34 pm

    Shuttle SX48P2 E
    BIOS SX48SE06
    Xeon X3363, stepping 10

    Running stable overclocked and no changes needed to BIOS for Xeon to be recognised correctly.

  • Oliver shaw February 27, 202112:25 pm

    Installed as instructed but the pc went into a boot loop on the windows screen


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.