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.

1,619 Responses

  • DannyMinh March 24, 201712:23 am

    Anyone success with Radeon Xpress 200? I did the bios mod (remove Celeron/ Pentium 4 microcodes) to the latest HP bios of HP Pavilion g2075l Desktop PC (mainboard ECS RC415ST-HM) to work well with Core2Duo E6600 (at 2.4/1066 and VT enable). Will it run 45nm Xeon if I further mod bios to remove all Pentium D microcode?

  • Detonalta March 25, 20177:45 pm

    Hello, I bought xeon x5460 and I have a POS-ECSG41BS that so far I have not found the bios driver, can you help me?

  • West View March 27, 201712:03 pm

    Thanks for the informative website. I replaced an E7200 with an L5430 for a media server/NAS. Minor issues with the motherboard BIOS: it recognized the Xeon, however, the microcode was incomplete and did not indicate the cpu supported the CompareExchange128 instruction (among other things [SSE 4.1], so Windows 10 64 bit would not install. Flashing the BIOS with the latest Intel microcode from your site fixed the problem. I’ve seen other people complain about issues getting Windows 10 to run on Xeons, and likely this is the problem: an incomplete implementation of the Xeon microcodes in the BIOS. It is interesting that programs like CPUID and Coreinfo only read what the BIOS tells them about the CPU and are not finding details from the CPU itself. Thanks again for all the instruction and information!

  • Thiago March 27, 20176:21 pm

    I bought a Xeon E5440 and it’s not working properly with my Asus P5N-D. May you help me please?
    I’ve been getting restarts every single time when the “starting windows” screen appears. So i noticed that when i lower the FSB from 333 to 315, the system works, even though the computer is slow…
    My configuration:
    Xeon E5440
    Asus P5N-D nForce 750i chipset
    2x2GB DDR2 800MHz
    Corsair CX430 PSU
    Thanks in advance!

  • db2x4 March 27, 20177:44 pm

    xeon 771 mods on stock bios.

    -Lenovo ThinkCentre M57e 9356/9487 G31 (G31T-LN, G31T-LM)

    Xeon E5440, X5450, X3363 work great at first start power on with stock latest bios without show any error message on post

    but speed is reduce can’t set the clock multiplier inside bios and need to add some microcode to show more instuctions on CPUID app.

    look like this mobo can support the 65nm clovertown xeon too after try the old 65nm celeron 420 the same architecture is work. I’ll test later when the x5355 arrive to me.

    -Lenovo ThinkCentre M57 Q35 (6068)

    X3363 work great at first start power on with stock latest bios but show error message “0167: no processor bios update found” on post and booting to windows.

    the system automatically run with full speed and we can set the clock multiplier inside bios and need to add some microcode to show more instuctions on CPUID app.

    xeon 5400 harpertown series -confirm not working


    -dell optiple 755DT Q35

    X3363 work great at first start power on with stock latest bios (022)

    the system automatically run with full speed and show all support instructions on CPUID app.

    xeon 5400 harpertown series -confirm not working


  • iscsi March 28, 20178:07 am

    Hi, All

    Intel DP43BF latest bios 088 working with E5450 C0 (SLANQ)/Windows 10 like a charm w/o any hacks.


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.