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

2,352 Responses

  • max August 5, 20181:49 pm

    I own a compaq hp computer which has a HP 2820h motherboard and a q33 chipset and am looking for the best processor my pc can handle. i would like to know which xeon cpu i can support.

  • neyoam August 6, 20188:20 pm

    I recently got my hands on gigabyte EP45-DS3LR (rev 1.0) and just wanted to report that my Xeon E5440 is working perfectly fine on that mobo.

    • dientm August 9, 20184:26 am

      I have EP45-DS3LR (rev 1.0) (updated BIOS with microcode) with Xeon E5462 but not POST.
      The mainboard working well with old E8500 and Xeon E5462 working well with Ga-G31.

      • neyoam August 9, 20189:20 am

        Sorry to hear that You’re having trouble with it. I’ve read on internet that xeons with 1600fsb can have difficulties with working on that mobo. After flashing Bios did You clear CMOS with jumper
        or load default/optimized settings in bios?
        If I were You, id probably get e5440/5450 and go with it.

        • dientm August 9, 20189:18 pm

          Thanks for your answer neyoam,
          I try several way but (clear with jumper, set default, optimized) it’s nothing.
          I’ll try with your suggestion and X3363 and report later.

  • Luiz Otávio August 9, 20189:14 am

    My Asus P5E-VM HDMI have been working very well for more than an year with a Xeon E5450. I replaced an core 2 duo E8400 with a great speed gain. Just as an advise, the Xeon 5450 is very cheap but you probably will need a new and good Cooler for it. But it worths.

  • merson August 10, 20183:12 pm

    it seems that the biostar g31m v7.x motherboard is not compatible with intel xeon E5420…

  • Arthur August 14, 20187:57 pm

    I have an Intel DP35DP, I wonder if any lga 771-to 775 works on my motherboard

  • Marcus Brown August 18, 20189:11 am

    Gigabyte GA-EP35-DS3R – E5430 (SLBBK) installed, easy, no problems.

  • Anthony August 22, 201812:16 am

    Hi, I have a motherboard G31 MV-K. Can I install some Xeon processor?

  • ModderX August 25, 201811:20 am

    Intel DG33BU – E5450 C0 did not work. CPU tested on two other mobo, works fine.
    Intel DG43GT – E5450 C0, X5460 C0 both work fine although the X5460 is above the supported TDP. E5450 E0 works but EIST does not work and reset button gives no video, Shutdown reboot or cold boot works fine.

  • Marcus Brown August 26, 201812:05 pm

    Pegatron IPIEL-LA3 in a HP 3120 sff box. American megatrends bios rev 6.07. xeon x5450 SLBBE.
    Install no problem, easy.

  • Marcus Brown August 30, 20185:57 pm

    pegatron IPIEL-LA3 update: E5430 (SLBBK) also worked fine.
    However I have been unable to get the cpu fan to idle, goes full blast all the time. Not with the X5450, nor with the much lower TDP (80W vs 120W) E5430. With a core-2 quad Q8300 (95W TDP) the cpu fan idled fine.

    Any suggestions appreciated…


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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.