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 $14 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

2,254 Responses

  • Robert Wilcoxson April 27, 20189:13 pm

    Asus p5q pro with both x5460 clocked to 3.9Ghz and x5450 clocked to 3.6Ghz. Left everything on auto except fsb clock. At 3.9 the 5460 starts to get a bit warm(mid 60s) with zalmon 9500 at. Bios mod was fairly idiot proof with mmtool. I must be crazy but I have my ga-z97-sli with 32gb of ram sitting in a box while I play with this antiquated hardware in its case. I also have a foxconn p41a g mb that worked with the x5450 but not the x5460. Both cpus are the older stepping. The foxconn board doesn’t seem capable of fsb more than 343 before crashing so overclocking is quite limited. Also difficult to find non ecc ram in 4gb sticks of ddr2 800(board only has 2 slots) for a reasonable price .

    • Robert Wilcoxson April 27, 20189:27 pm

      I’d also like to add that an 1/8″ router bit in a Dremel worked fine to cut notches in the cpu pcb instead of hacking on the mb.

  • Alex_pnz May 4, 20185:43 am

    Motherboard Asus P5Q Turbo – flashed your firmware for 771 – normal flight to Core Duo E8400, then inserted Xeon 5450. At the first download flown Windows, tried several more times – the same thing. Started from the disk memtest – solid memory errors. Tried all the bars – the same thing. Changed back on the Core Duo E8400 – it’s all right. In this case, the percentage is normally displayed in the BIOS and does not produce errors.
    I tried the other mother P5QL-CM – the same procedure – both of them work on firmware under 771.
    Can the BIOS on the Asus P5Q Turbo be broken?

  • batyanko May 7, 20188:45 am

    Tested Xeon E5410 on the following boards:

    1. Lenovo L-IG41M2 V. 1.0 (Lenovo ThinkCentre A70), Socket G41: Seems to work fine at FSB 1333 MHz.

    2. ASUS P5B-V, Socket P965: Runs with POST warning and at reduced clock due to FSB at only 1066 MHz.

  • John Bradley May 10, 20188:22 pm

    Just running an X5450 in an ASUS P5P41D works ok bar the Update you BIOS message.

  • Rad May 11, 20187:33 pm

    MB Asus P5N-D rev 1.02G
    Xeon E5450 E0 revision – two diffirent processors
    Full reset of BIOS – through jumper

    MB start with default settings. During OCCT tests two processors are over heating.

    I have nice cooler Golden Orb II

    Best regards. Rad

    • Anonymous May 13, 20184:02 pm

      Maybe OCCT reads temperature incorrectly? TjMAX for E5450 = 85C. Many programs read temperature with TjMAX = 100C (+15C increase). Use realtemp from http://www.techpowerup.com and set the correct value of TjMAX.

      Cooler looks to be efficient enough – CL-P0220 can’t support CPU over 130W and it’s better for 90W CPU use. But E5450 TDP is 80W. Check settings in BIOS for voltage, FSB etc., check thermal paste and cooler mounting.

  • Doniyor May 11, 20189:45 pm

    I cannot find bios to my mothetboard. On my motherboard written M143D REV 2.0. What should I do ?

  • Doniyor May 11, 20189:46 pm

    Just I wanna update my bios.

  • Emad May 12, 20185:56 am

    I tried this mod on my system and it worked! Guess this comment would be useful for those who have the same board as mine!
    My system configuration is:
    Motherboard: Gigabyte GA-EP43T-USB3 (rev 1.0)
    BIOS version: F4
    CPU: Intel Xeon X5460 3.16GHz
    Works perfectly on Windows 10 (version 1803 build 17134.48). Though some Intel Processor Diagnostic Tool tests didn’t pass and failed!
    Didn’t tried linux but it DOES NOT work correctly with Mac OS/hackintosh and have some sirious issues!

  • Bongeng May 12, 20181:30 pm

    Help me, please?
    I tried to install xeon e5450 for replacing my old processor Core2duo e8400, but I have problem with my windows after the installation.
    At the first boot time, it became so long, I waited until 7 minutes for running into the windows, and the cpu usage always at 50%, it made my windows very very lag.
    Finally, I replaced my e8400 again, and my windows was going back to normal.
    Here is my Pc:
    Motherboard Ecs G41T-R3
    Ram 2 x 2GB 10666
    Windows 7 Ultimate 64bit
    Psu FSP Hexa 500w

    • Alex_pnz May 14, 20184:10 pm

      C1E/C-Step/EIST – Disabled

      • Bongeng June 12, 20183:40 pm

        Thank u very much, it’s work.

  • Atharva May 16, 20182:32 am

    MSI G31TM-P21 (MSI 7529 v1.6)
    i actually have the same board so i just wanted to know did you add any microcode to the bios ,the last bios update from MSI was Version 4.7 (A7529IMS.470) and i am running the same 4.7 bios version.
    Curenntly using Intel E5400 dual core.
    So if i use E5450 will i need to update the microcode for my bios???


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.