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 $12 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

2,267 Responses

  • David February 16, 20182:37 pm

    Gigabyte GA-G41MT-S2P Rev. 1.3
    Xeon X5482 Stepping 6 Rev C0
    ** Boot Ok in FSB 1333Mhz can overclock to max 1360Mhz

  • pinux February 20, 20181:28 pm

    Hi ,
    i have problem to install windows 10 32/64bit same result with error 0000225 after bios microcode update xeon L5420 slarp stepping CO or sbblr stepping EO I have both of these L5420 Motherboard is P5G41T-M LX with 8gb ram installed working perfect Both L5420 in bios are cpuid 0667
    this is ok for co stepping but not for EO stepping this would be 067A, i cannot see this cpu bios information
    xeon L5420 EO /CO stepping microcode needed for my p5g41t-m lx bios version 1101
    Thank for help

  • Ismar February 21, 20185:45 am

    Motherboard: Asus P5P43TD
    Bios: Latest
    Processor: Xeon E5440 E0 (SLBBJ)

    Result: Does NOT work, stuck on Windows 10 logo when booting up EVERY time tried. Tried with old and updated BIOS, same result.

    Modding: After modding Bios microcode, everything WORKS just fine.

    • Ismar February 21, 20185:50 am

      Mobo’s rev is 1.00G

    • AhSam February 23, 20189:23 am

      where you buy Mobo P5P43TD?

  • raka February 24, 20181:02 am

    I’ve tried to fix my p5q + x5460 with boot up warning. “Update bios recommended. To ulnleash cpu’s full power”. And i followed instruction to attached microcode with latest bios 2209. But the warning still appears..

    • Goran Jankovic March 3, 201810:44 am

      you didn’t attack the right microcode. Identify your cpu id. For example, e0 e5440 name is SLBBJ (it’s written on the cpu itself). Then, google for “cpu world XXXXX” where xxxxx is your cpu name, like SLBBJ and open the first result. Under Architecture / Microarchitecture / Other, you’ll find CPUID. You need to mod your bios with the microcodes for your cpuid, and don’t forget to delete any old microcodes for your cpuid which might already be on the bios.

      • Goran Jankovic March 3, 201810:44 am


    • Goran Jankovic March 3, 201810:46 am

      p5q is basically identical with P5Q Turbo which worked flawlessly for me, there’s no reason for it not to detect the cpu if you modded the bios correctly and flashed it afterwards.

  • Derek silver February 26, 20189:36 am

    X5460 Worked on Dell optiplex 380. I used a larger heatsink from an optiplex gx520. The heatsink on the 380 is only rated for 95w I think. Bios recognized it right away.

  • Ruben February 27, 20187:24 am

    x5460 worked on my Gigabyte p35c-ds3r. Without any required bios or microcode updates.

  • bentech March 2, 20186:56 am

    hello guys am having a problem installing OS on xeon x5450 in my dell studio 540 LGA775 it got staged at windows start up. i have tried both 32 and 64bit OS Windows 7 to Window 10. any help please?

    • Goran Jankovic March 8, 20185:15 pm

      I had the same issue, os hangs on windows logo. After turning of “enhanced speed step” (I think that was the name of the feature) in cpu section of the bios, it worked fine.

  • Goran Jankovic March 3, 201810:41 am

    Asus P5K Pro rev. 1.02G

    Added e0/1067h microcodes to the latest 1303 and flashed it (there was no room on the bios so I had to delete some old microcodes so I could insert those for 1067h).

    E5440 e0 SLBBJ works flawlesly, overclocked it to fsb 400 = 3.4GHz.

  • Spike March 3, 20182:14 pm

    Will a X5470 work with a G31 / ICH7 chipset it says someone tested a X5460

    Gigabyte GA-G31M-ES2L G31 / ICH7 1333 ≥ 130 Q9650, QX9650 All
    Worked: X5460 (E0), E5462, E5450 (C0), E5405 (E0)

    i mean if noone has tried it, ill try the mobo i got for free and cpu is only 30-50 bucks ill have to mod the board, cpu, and bios but its worth a shot kind of fun project


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.