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 $30 (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


Leave a reply
  1. ronan

    Hi syn,guys,

    I was searching around cpu stepping,but I am confused as my knowledge in this is 0
    Can someone help me to choose a right xeon for my platform?
    I was about to buy an X5460,but X5450 will do if no choice.
    In link that syn provided is that HP dx2400 worked with X5450 but there is no mentioned what stepping C0 or E0 was this cpu.
    Do you think all xeons with both stepping code will work in my case or what is this code actually mean?
    Thanks for any answer.

    Regards Ronan

    • Pedro

      I think that when it comes to stepping, there is no compatibility problems so its just better to get the later model (that should be the E0)

  2. ronan

    Thanks Pedro,
    Yes you’r right,I found this on google as well and I ordered E5450 SLBBM which is E0.

    Regards Ronan

  3. Mr.Jak

    Add e5450 (e0) and L5430 to XFX 790i ulta
    Also this chipset supports all 775 chips, including pentiums.

  4. CroMagnaTron

    I wrote about successful X5450 in a Dell inspiron 518. Well it has been a while now and it is still running great. I ran a benchmark and it registered 3081Mhz also in details it lists the following – x86 Family 6 model 7 Stepping 6. Also MMX yes and SSE Yes, SSE2 Yes.

  5. Davide


    I successfully installed an L5420 on a Biostar “G31-M7 TE” (ICH7).
    The motherboard booted without requiring any firmware update. I’ve set the CPU multiplier to 7.5, with a FSB of 333MHz and a CPU frequency of 2500MHz.

    Although the system runs and is stable, I can’t let it boot with more than 2 GB of RAM installed. May the MB’s RAM compatibility be affected by this mod?

    The RAM banks which failed to boot are one pair of identical
    “2GB (2x2GB) Dell – Hyperam DDR2 PC2-6400U 800MHz 126×8″

    • Davide

      * 128×8, not 126×8.

  6. ura soul

    just completed modding an asus P5QC motherboard to run a xeon X5482 @3.2GHz.
    so far all is well. :)

    the BIOS is the latest from ASUS (2009).
    the FSB is 1600
    multiplier is 8

    CPU stepping is 6
    CPU revision is C0

  7. ronan

    Hi all,
    Just moded HP dx2400 with E5450 SLBBM which is E0.
    System working on first time,with latest bios from 2009.
    Everything is perfect except cpu fan is spinning on max rpm which is very noisy.
    Do you think that microcode update will help on this?
    If yes I will perform the bios update with correct microcode.

    Thanks&Regards Ronan

  8. Dinsdale_P

    I’ve tested L5410 (C0) on two boards so far, here are the results.

    Asus P5B Premium (P965 chipset): boots up to windows after some tinkering, unstable as hell, freezes randomly and on such magnificent events as switching to Aero… unusable. but again, it’s an old board, which doesn’t even play nice with 45 nm dual cores (no overclocking!).

    Asus P5KPL (G31 chipset): works perfectly, with a few caveats – the board has an FSB wall of 343, so no overclocking, and lacks voltage control, so it overvolts like a monster – 1.2V where 1.05V would be more than enough.

    Next up on the menu, MSI P43 Neo!

  9. P4M900-M7 FE rev 7.0

    I confirm that Biostar motherboard P4M900-M7 FE version 7.0 works with X5260, it has a VIA P4M900 chipset that works with a max tdp of 95 watts, however due to FSB being below 1333 (1143) can only operate cpu at 2.89 Ghz, the irony here is officially this cheap board only supports up to an e7600, though another site lists up to a q8300, I’m not 100% sure this will work however given that I updated the microcode in the BIOS I’m going to test it with the L5408, which is a 45nm quad-core with an incredibly low 40 watt tdp, if this works I’ll report back…

  10. ASUS P5G41C-M

    I confirm that the ASUS MicroATX board P5G41C-M works with the X5470 perfectly@3.45 Ghz. The board supports 1333fsb max so I’m fairly certain that the X5470 is the max Xeon for this particular board, however considering it’s microATX I’m extremely happy with the results, now if I can just keep the cores from getting too hot!!! Using with an HD5770 (oc’d) and 8gb curcial ballistix low-voltage ddr3 it runs Crysis 3 at 1080p with medium settings at an average 30 fps!!! I’m going to need a more powerful gfx card if I want to max out the settings in the game however still very impressed so far :D

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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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