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 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 $23 (about $70 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


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  1. LAwrence

    DP/N 0p301D <— Dell Vostro 220 board made by Foxconn Dell Vostro 220 Motherboard Specifications.


    Processor Support Socket LGA 775, Intel Core 2 Duo Quad, Core 2 Dual-Core, Pentium Dual-core, Celeron.

    1333/1066/800 MHz

    North Bridge – Intel G45
    South Bridge – ICH10R
    Integrated Graphics

    Intel GMA X4500 HD

    2 * 240-pin DDR2 DIMM slots Supports Dual Channel DDR2 800 MHz non-ECC, un-buffered memory (Max 4GB)
    Expansion Slots

    1 * PCI Express x16
    1 * PCI Express x1
    2 * PCI

    4 * SATAII 3Gb/s connectors
    Supports HDDs, Internal Solid State Drive (SSD)

    Realtek ALC662 – Definition Audio

    Realtek RTL8111C – Gigabit 10/100/1000Mb/s
    Rear Panel

    1 x VGA port
    1 x Audio I/O
    1 x Serial port
    1 x RJ45 LAN port
    1 x PS/2 green for mouse
    1 x PS/2 purple for keyboard
    2 x USB 2.0 ports

    1 x Battery socket (3V)
    1 x CMOS reset jumper
    1 x USB headers
    1 x 4-pin CPU Fan connector
    1 x 3-pin Rear Fan connector
    1 x 4-pin ATX 12V Power connector
    1 x 24-pin ATX Power connector
    1 x Front Audio header
    1 x Front Panel header
    1 x IEEE 1394 header

    Flash BIOS
    Form Factor

    Micro-ATX Intel Xeon E5450 3.0 GHz quad core Socket 771 server CPU SLBBM 12M/1333 64-bit, 80W

    Here is a 64-bit quad core Socket 771 server CPU from Intel running at 3000 MHz. It uses a 1333 MHz front side bus and has a generous 12MB L2 cache, E0 stepping and the "Harpertown" core. The unit booted windows 10 without problem,but needs a microcode update for sse4.1 ect, and the tjmax settings. Fans run 100% and dell bios won't allow adjusting from outside that I can find. CPU-Z shows proper specs for processor and it ran basic test before being switched back out.

  2. OverNight

    P5k MVM/S WortMann: black screen and won’t boot.

    Microcode added and tested with E5430 and E5440.

    Yes, all i’ve cleared CMOS. Then, after switch on, this is the behaviour:

    * no beep, the fan runs, green light on for 3 secs,
    * then all stopped for 1 sec and finally,
    * the same thing (so no beep, the fan runs, and green light on ) without any other stop.

    the motherboard works fine with an DUO E8500….

  3. Wojtan

    MSI P45 neo2 Xeon X5260,X5270,L5420,E5420,E5440,X5450,X5460 ….. all works :)

  4. Nathan

    Thank you for the guide. Mod is working perfectly. Upgraded from C2D E6750 to Xeon E5450 for $22.

    Xeon E5450 SLANQ C0
    Gigabyte P35-DS3L rev A2, BIOS F9

    MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, EM64T
    No microcode update needed, speedstep works normally.

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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.


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