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



Detailed instructions for completing this MOD

Don't forget to fully reset your BIOS after completing this MOD - This is explained toward the end of these instructions, and it usually solves the majority of the problems that we hear about.

Disclaimer: We've done our best to explain this MOD in the safest way possible, and thousands of people have successfully completed it. However, please attempt this at your own risk. We are not responsible if your system is damaged during this process.

Things you'll need

Step 1 - Install the latest BIOS, and make sure your motherboard is compatible with your Xeon

BIOS updates often add support for new processors, so you have the best chance of this working with the latest bios for your motherboard.

If you haven't done this already, you should also verify that your motherboard is compatible with the Xeon processor you want to install. If it isn't, your system will likely fail to boot.

Step 2 - Remove the two plastic tabs from the LGA 775 socket, so you'll be able to install LGA 771 CPUs

This step was already explained earlier in this guide.

Step 3 - Attach the adapter to your Xeon processor (the triangle/arrow on the adapter should point toward the triangle on the CPU)

Static electricity warning: The circuits on the processor (above where the adapter goes) are sensitive to static electricity, so touch a screw on the back of your computer to discharge yourself before handling it. If you're using metal tweezers, it would also be a good idea to discharge them as well.

First, wash your hands, so you don't weaken the adhesive when you handle the adapter.

Make sure the top-right edge of your adapter is only 1 pad long

If you look at the adapter shown below, you'll notice the top-right edge of the adapter (with the letter T) is only 1 pad long horizontally and doesn't cover any of the pads to the right of it. This is how your adapter should look when you attach it to your Xeon processor (some adapters may have something else in the top-right corner instead of the letter T).

If the top-right edge of your adapter is longer than the width of 1 pad, you'll need to cut it to look like the picture below.

LGA 771 to 775 Adapter

LGA 771 to 775 Adapter

Remove the cover from the adhesive

The latest revision of this adapter comes with adhesive preapplied to the bottom of both ends of the adapter, which will help it stick to the processor. If yours does, peel off the protective cover to reveal the adhesive.

Safest way to remove the adhesive covers

The easiest way to safely remove the adhesive cover is to hold the adapter right below the cover that you want to remove. You then peel upward (toward the top of the adapter) like you're trying to peel off a sticker.

Just be careful to not damage the 2 metal pads in the center of the adapter or overly bend the adapter when removing the covers.

If your adapter isn't sticking securely enough, you can also use double-sided tape to secure it to the processor

The easiest way to do this is to attach the end of the adapter to a big piece of double-sided tape, and then cut around the adapter using the little scissors that some people use to cut their fingernails. Just make sure the tape only covers the ends of the adapter (so it doesn't cover any of the pads on the processor).

Line up the adapter on the bottom of the Xeon cpu

Carefully lay the adapter onto the processor and align it as shown in the previous picture. Tweezers are helpful here.

Make sure the triangle on the bottom of the adapter is pointing toward the triangle on the CPU (some adapters have an arrow in the bottom-right-hand corner instead of a triangle).

Important: Take your time and make sure the adapter is aligned exactly as shown in the picture (you may want to use a magnifying glass to verify). If it's off by much or covering some pads that it shouldn't, your system may fail to boot.

When you're confident the adapter is lined up correctly, press down on both ends to secure it to the processor.

Now double check that the adapter is still lined up correctly and is tightly connected to the processor. You don't want the adapter moving when you install it into the socket.

Step 4 - Correctly install the Xeon into the motherboard socket (the triangle on the CPU needs to be aligned with the triangle in the socket)

Make sure the triangle on the processor is lined up with the triangle in the socket as shown in the picture below.

Important: Ensure that the processor is fully seated in the socket before closing the lid (try wiggling the CPU a little). If the plastic tabs were not cut off fully, it may not make contact with all of the pins in the socket. This is a common installation error, and if this happens, your system will likely fail to boot.

Place the cpu in the socket

Place the cpu in the socket


Step 5 - Do a FULL BIOS reset (use the 3-pin motherboard reset jumper, and then load the default BIOS settings on the first startup)

Most motherboards have a 3-pin reset jumper that will allow you to fully reset your BIOS (this is usually mentioned in the manual). If yours doesn't, you can also remove the CMOS battery (it looks like a watch battery) to reset your BIOS.

When you start your system for the first time, make sure you also go into the BIOS and load the default settings.

If you would like more details on how to correctly do these steps, check out the following pages:

Note: Your system may cut itself on and off several times before booting up correctly the first time. This is normal with some systems, and it should start normally in the future.

Step 6 - Finishing up

If you run into any problems, please read the troubleshooting section of this guide. It covers most of the common things that can go wrong.

And if you still need an adapter or a Xeon processor, check out the following links:

Please let us know if this mod worked on a motherboard that isn't in our list

Leave a comment with your:

  • Motherboard model number (and revision if it has one)
  • Xeon model number (and stepping if you know it)
  • (Optional) chipset, max FSB, max TDP, and supported LGA 775 processors

And we'll add this information to the motherboard compatibility section, which will help other people that are also using your motherboard.

1,718 Responses

  • atechol June 17, 20174:02 am

    Hello everyone.
    I have been researching the 771 to 775 mod for awhile now and just wanted to say thanks for all the information you guys have put together here.

    • Han Solo June 17, 20175:22 pm

      I have done this twice. And I have to say to me it is much easier to just take a small round file and file some notches into the XEON CPU using an old core2 as a template. It is very easy to mess up the pins on the socket trying to get the plastic tabs out of there and you can take your time with the file and do a pretty neat job with not much effort.

  • atechol June 17, 20174:05 am

    Bbtw, I just successfully installed an x5450 in a HP Pro 3000 Microtower with the information found here. Thanks Again!!!!

  • paul ferguson June 17, 20179:23 am

    Just finished the mod with a Asus P5K PL SE and a X5460 ,all running OK but like a few other posters have said in order for windows and various programs to identify the Xeon and not keep reporting my old Core duo 8500 i installed the new bios 3 times and did 3 resets and load defaults .

  • Han Solo June 17, 20175:23 pm

    I have done this twice. And I have to say to me it is much easier to just take a small round file and file some notches into the XEON CPU using an old core2 as a template. It is very easy to mess up the pins on the socket trying to get the plastic tabs out of there and you can take your time with the file and do a pretty neat job with not much effort.

  • Peter June 19, 201710:57 am

    Confirmed work x3323 with Dell Optiplex XE SSF

  • Tina June 19, 20176:02 pm

    Thank you very much for all of this usefull information !

    I am not trying to fit a LGA771 CPU into a LGA775 board, so please excuse my question.

    I want to mod my two (dual) X5365 Xeons with this BSEL in my 771er board.

    1. What can I expect when doing this ? Does this hoover the FSB ?

    2. My board has an Intel 5000x Chipset and my two X5365 Xeons are listed as the biggest
    supported Socket 771 CPU’s. What about the newer 54xx Xeons ( only those for LGA771
    with the same matching FSB ) Do these also fit into Socket 771 and work ?

    Cheers Tina

  • Domenico June 22, 201712:48 pm

    Hi to all, i just want to know if Xeon E5472 (FSB 1600, TDP 80W), Xeon X5460 (FSB 1333, TDP 120W) and Xeon E5450 (FSB 1333, TDP 80 W) are compatible with my MoBo Asus P5G41C-M LX (FSB 1333, TDP I don’t know)

  • Vegethalia June 23, 20173:10 am

    Hi, tested successfully a xeon X3360 with an Asus P5E3-Deluxe.
    Easily overclockeable to 3.2ghz+ with stock voltajes.

    Thank you!

  • atechol June 23, 20174:55 am

    HP Pro 3000 MT Pine Row Motherboard Xeon X5450 Mod.
    I posted earlier this week saying this mod was successful and it was. After spending several days loading software (50 games) and all other software. I noticed that the processor was reporting differently on several programs. It would post Xeon X5450 @ 3000 MHz , then showed 2333 MHz behind it. Turns out that the old bios was holding it’s multiplier at 7 instead of letting it run at 9. I followed the instructions for updating the AMI bios here on the site, modded the bios file and flashed it, reset the jumper pin and booted. After resetting my bios settings on the second boot all is well now. For anyone looking for a cheap gaming solution, this combo with 8 gb ddr3 10600, a 450 watt psu and an XFX R7800 Ghost (HD7870) makes for a quite capable gaming machine. You will need to adjust some settings but this lil machine is running Doom, Fallout 4, Skyrim, Sniper GW3, Deus Ex, ETC. Once again thank you to everyone who keeps this site updated and to those of you who have posted your experiences with these mods. I would have never attempted it, let alone completed it, without your help. Thanks Again.


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.