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.

2,274 Responses

  • Marco March 15, 20194:57 pm

    Hi, i have an ASUS P5QD Turbo and a xeon e5450: PC boot up till Windows logo, then it freeze and shuts down; any solutions?

    • Everton March 20, 201912:59 pm

      Same here

  • Fourfree March 15, 20197:10 pm

    Hi all

    Trying to use a Asrock G41C-VS motherboard with bios mod. Having no luck with a E5462 and X5460 cpu. Both cpus work in my Gigabyte GA-G31M-ES2L with mod. Can not find much info with this motherboard. Has anyone good any working info of Asrock G41C-VS.

    Any information welcome.

  • Marco March 19, 20196:42 am

    Hello everyone,

    Is the Gigabyte GA-73PVM-S2H motherboard (rev. 1.0 with F9F BIOS) compatible with the Xeon E5405 CPU ?

    Thank you for your help.

  • Havsfrun March 28, 201911:52 am

    Installed L5420 into my ECS P45T-A
    Bios Version: 080015, Release Date: 05/20/2009.
    System boots without any modifications.

  • ASrock G-41M-S March 31, 201910:24 am

    Здравствуйте! У меня материнка ASrock G-41M-S ,какой подойдет проц?

  • Armand March 31, 20192:08 pm

    I have tested Xeon 3.16GHz X5460 C0 stepping , with Asus P5K SE mobo , for almost one week. The X5460 has passed Intel Diagnostic Tools and Tests. However, Asus motherboard still needs the xeon microcodes, otherwise I have to press F1 to resume and continue the booting process. Recently after searching the bios microcode’s mod how to , I got the modified P5K SE bios mod from overclocker.net . The bios is working fine, no problems. I flashes the bios and it works flawlessly.

    However , the only ON GOING problems I still experience, the computer sometimes is very difficult to turn on ….. scenario #1 : After I press the power on button, the computer turn on for 1 second, and then shut off abruptly , and 1 second later , the computer turn on back again and continue windows 8.1 booting process. Scenario #2 : the computer turn on for 1 second , and the shut off abruptly and stay dead until I turn off the master power switch behind the psu for few seconds , and I restart the process again .

    Anyone have solution(s) to overcome the problems ?

    Bios reset , checked
    Latest Bios with Xeon microcodes, checked
    PSU is 650 watts with dedicated three 12v rails . I am very sure my power supply is more than enough.
    Windows 8.1 , checked , no problems.
    Intel Diagnostic Tools and Tests , checked , all passed .
    CPU temperature 72C , open casing .
    CPU voltage , Auto , 1.140V
    FSB Overclock , 360 mhz x 4 = 1440
    CPU Overclock , 360 mhz x 9.5 = 3420

  • SteppoBlader April 2, 20194:09 pm

    Hi there! I’ve recently bought an Asus p5k64 ws mobo to use with a xeon x5470. No matter how hard I tried it did not work. I followed the turorial from beginning to end. The rig goes on and off continuously in an everlasting loop. I have injected the x5470 microcode into the latest bios, tested all the preinjected bios I cud find still to no vail. Follow the procedure to the letter from flashing the bios to reset the cmos, tried reseating the cpu, replacing the sticker, switching ram sticks, currently running 2 samsung 4gb ddr3. When I go and use a q9550 from the other rig it works flawlessy. Even if on this page ia stated that the mobo is fully compatible with such cpu mine just it is not. Any help will be greatly appreciated. Best regards

  • SPIKE April 8, 201911:15 pm

    I have a Gigabyte mobo GA-EP45T-UD3R I went to the site downloaded bios for the mobo but its a .F2 File how can i get it to be a .ROM I tried to rename it like this site said to do nope didn’t work.

    Any help would be great thank you (-_-)

  • soteris April 10, 20192:30 am

    MSI G31M3-F Intel® G31 Chipset Supports FSB 800/1066/1333 MHz
    worked with E5440 1067A SLBBM
    bios version 1.3


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.