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

2,415 Responses

  • Retrorockit June 28, 20207:15 pm

    The Dell Optiplex 380 supports the 120W X5470 Xeon. It needs a BIOS from BIOSMods.com.
    I’ve seen X5460 running in them also.
    You show it as having a 95W CPU limit which is not true.

  • Nacho July 5, 20201:39 pm

    Xeon E5440 on Biostar G31-M7 v6.7 full working after microcodes update. Motherboard initially recognized CPU but not at full core speed. Microcodes update and bios reset must required.

  • marcelo macedo vieira July 7, 202010:51 pm

    ola, vocês postaram que fizeram teste na placa mãe Asus P5N-E SLI ,
    que suporta Core 2 Duo E6850
    trabalhando com o processador xenon x5450 , os Nó são diferentes . essa diferença dos nó 65nm e 45 nm pode dar problema no futuro?

    hoje no aliexpress está muito bom esse modelo x5450 por R$ 88

    outro total compatível x5355 por R$ 72 ,e é bem inferior 2,66/8/1333

    posso optar pela x5450 ?


  • Julio Terrazas July 15, 202012:15 pm

    Intel DP43TF
    Chipset Intel P45/P43/G45/G43 rev. A3
    BIOS NBG4310H.86A.0107.2011.0112.1625
    Xeon X5450 funciona bien, pero con altas temperaturas con disipador stock

  • Дмитрий July 26, 202012:58 pm

    У меня материнская плата asus p5b хочу поставить процессор х5460 3.1мгц. сейчас стоит процессор intel[m)core(TM) 2 Quad CPU Q6600 @2.40 GHz 2.39GHz. что для этого надо подскажите и стоит ли брать этот процессор?

  • Alex July 27, 20204:12 pm

    Hi, I just tried to set up a modded X5460 (sold already prepared on ebay) on a Gigabyte GA-P35C-DS3R Rev. 2.1 and add 8 GB DDR3-RAM (was 4 GB DDR2 before).

    According to the tutorial I added the microcodes to a BIOS binary (F4) and flashed it. It seemed to work, the new Version F4 was shown during boot and in CPU-Z.

    Then I installed the Xeon and new RAM, but the PC didn’t boot. It just turned on and off repeatedly.

    So I removed the 2 RAM bars, SInce this, there are short beep codes indicating a power failure. But the motherboard supports Core 2 Extremes with up to 135 W, the Xeon should have only 120 W. The power supply servers up to 500 W, I want to believe this is enough. :)

    I don’t know what and how to test next for just seeing a blank screen. Any hints? Would be very appreciated! Thanks a lot.

    • Alex July 28, 20205:11 am

      I forgot to say the Xeon is a SLBBA with an E0 stepping.

      • Alex July 28, 20208:02 am

        Oh, and of course I cleared the CMOS. Several times, even took the battery out.

  • dhnebdbf August 3, 202012:11 pm

    IPIEL-LA3 *is* compatible:

    – add microcodes to BIOS
    – enter bios setup using *CTRL-F10*
    – In “power”, set “Intel(R) C-STATE tech” to “disabled”
    – everything else in “power” can stay enabled

    Windows 7 will install without the microcode and is sufficient for modifying and flashing the BIOS.

    Arctic Freezer 11LP fits the board and SFF case, but then a custom wire is needed to plug the chassis fan in. Stock cooler is okay for E-processors, but might not be for X-processors.

    Tested: Xeon E5450, IPIEL-LA3, latest BIOS with microcodes injected, HP SFF case, 100% working, 3.0GHz.

  • Doctor Empathy August 3, 20206:14 pm

    Tested: Xeon E5420 on a Gigabyte GA-G31M-ES2C rev1.x, with latest BIOS microcodes applied. Working on WINDOWS 10, no issues at all.

  • Skystranger August 7, 20205:18 am

    I have bought X3363 and tried it on Asus P5E3/ Now i need to update BIOS. IF the official BIOS from Asus site will be suitable or it doesnt contains id for Xeons and i must find antoher one?


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.