LGA 771 to 775 Adapter (MOD) – Run faster Xeon CPUs in a Core 2 Quad motherboard

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2,431 Comments

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

2,431 Responses

  • Lex March 12, 20207:26 am

    ASUS P5N-E SLI Worked: E5450 (E0)
    MSI G41M-P33 Combo Worked: E5440 (E0)

    Reply
  • DiegoT March 20, 20207:50 pm

    Hi, i bought a Xeon E5440 adapted for LGA775 from AliEx. I tested it and my Mobo and Bios recognize the Xeon, shows the exactly model name, clock and everything. But it doesn’t boot up the Windows 10 Pro from the SSD and not even the Windows installer from pendrive. So i’m stuck in a boot loop with this Xeon CPU, but my old Core2 E7300 still works great after the test.
    I have a Gigabyte GA-G31M-ES2L, it’s listed as compatible and tested by Delidded. Right now i’m updating the Bios to the latest and going to test the Xeon again.
    BUUUT if it’s still not booting, what can i check next? Can maybe be the case of putting a modded Bios? Because it pass the Bios boot and reach the Windows 10 boot image, but in a blink it restart…

    Reply
    • DiegoT March 20, 20208:39 pm

      I forgot to say, it’s a SLBBJ Xeon, so the stepping is E0

      Reply
      • iRon March 22, 20206:15 am

        did you clear the CMOS after you flashed the BIOS with the modded microcode?

        Reply
        • DiegoT March 22, 202010:15 am

          i solved it \o/ i put a little more effort in building my own Bios Mod

          Reply
  • chomkers March 26, 20203:21 pm

    shuttle SG45H7 work with x5470 in FG45 motherboard (with bios mod)

    Reply
  • ryanzb111 March 27, 20204:42 am

    ASRock G43Twins-FullHD modded bios, running Xeon X5450!

    Reply
  • ryanzb111 March 27, 20204:57 am

    @Alex

    Here is modded BIOS for P5KPL-ASUS-0805 with 45nm microcode injected.
    Although I do recommend you learn how do to this yourself, as it is a fun project.

    Make sure you have the pin mod sticker!!
    And slice the plastic CPU tabs off your motherboard with an x-acto knife.

    https://www.sendspace.com/file/3sj6wz

    Reply
  • skysouto March 27, 20208:38 pm

    ASUS P5B-E PLUS / P965 / FSB 1333 / TDP 130W / Q9650, E8400, E6600

    Worked: X5470 (E0) with Xeon microcode added to bios 0638 due to wrong over temperature advice on boot.

    After that, everything was perfect.

    Thank you so much !!!

    Reply
  • ryanzb111 March 28, 20205:28 am

    BIOSTAR G41D3+ modded bios, running Xeon X5460!

    Reply
  • hailey morales March 31, 20205:08 pm

    hi im using a hp dx2400 motherboard i installed a xeon 5460 after bios update but im only getting 2 cores insted of 4 pliz help

    Reply
  • Steven April 9, 20201:41 pm

    I managed to get an x5460 E0 working on an MSI ms07592 v6.0.
    It’s running 8GB DDR3 @1066MHz.
    So far I’ve OC’d to 3.22GHz using FSB and 3.3GHz using an MSI utility. It’s sitting at 20°C idle.
    To install windows 10 I had to use a C2D and it ran w/ the Xeon but wouldn’t dipslay it. I upgraded the BIOS to the modded version and it feels pretty snappy.
    I also ordered an E5430 which I plan to use on an ASUS P5Q3.
    I’m really thankful for this website.

    Reply
  • pawlosek April 17, 20201:00 pm

    Another happy Xeon user.

    CPU: Xeon X5450 SLBEE (E0) – ordered via aliexpress $12
    Mobo: Asus P5K Premium
    RAM:
    2 x 2GB RAM OCZ2RPR800C42G
    2 x 2GB RAM OCZ2P10662G
    GPU: GTX760 2GB Palit
    PSU: Tagan BZ600W

    O/C – didn’t try above 3.6 (lack of experience ) 1.285V || RAM at 760MHz

    Reply

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.