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.

2,046 Responses

  • Rob May 17, 20188:57 am

    Hello, I have a question. I have a motherboard (ASUS P5KPL-VM, which has G31/ICH7 chip), then … what would happen if I install the Xeon X5470 ?. The maximum of TDP. of this motherboard is 130W., I wonder if I install that processor on this board.

    Could it get to overheat ?

    Could the board die? or

    Would it need better refrigeration?

    I’ve also been seeing that it has 3 vrm phases without a heatsink, I do not know if that can cause something in the heating up.

    Or directly move from this board and upgrade to a more current system like the 8th Generation of Intel?
    Thank you.

  • vinod May 18, 20181:08 am

    I bought a asus p5g41t-mlx motherboard and I have done the bios update with the micro-codes, but after i power up the mobo with my xeon processor e5450 (which is modded), it stays a for about 20 secs and switch off automatically…. What should I do?, is there any changes to be done with the cmos ratio/ values? Please help
    My specs are – ASUS P5G41t-mlx
    Xeon e5450
    2GB DDR3
    palit 750 ti dual

    • kjafkjkaf May 20, 20182:45 am

      change the cpu fan it turns off cause of overheat

  • tom May 18, 20189:56 pm


    I have a Q9550 and I would like to make a mini-itx HTPC. The best mobo that I can find is the Intel DG45FC.

    Some reputable websites say this CPU and mobo are compatible, yet, others say they are not compatible.

    Please help!!! Will the Q9550 work with the DG45FC?


  • Kevin May 25, 201811:25 pm

    Hello i had some problem that my xeon is too damn slow the xeon even cant load windows in 4hours.

    But i do few tricks that i install windows on my pentium dual core and then i replaced to xeon procesor. ZThe boot works but take around 10minute to go to the desktop, and the cpu load is soo danm high, cursor stuter (even its fresh install) .if im going to reinstall windows with xeon processir it will freeze. ( in this trick if i go to safe mode, the xeon worked fine without any problem)

    Hope you can solve my problem

    I cant install windows 7 with xeon l5420, the installation takes forever so i do it with my dual core and swap the processor to xeon.

  • john789 June 1, 20189:53 pm

    I am very interested in doing this, as I didn’t even know that it was even possible, but I need some help.

    Here goes:

    My motherboard is a Gigabyte GA-P35-DS3L version 2.0 with 4 sticks of PC2-6400 2GB 2X1GB DDR2-800 for 4Gb of ram and a E2160 cpu overclock to 3.0 ghz. I checked the motherboard compatibility list and my mb is approved.

    I read the article here https://www.delidded.com/lga-771-to-775-adapter/

    But I still have a few questions, do I need to mod the bios to Update CPU Microcode in an Award BIOS? If so, I would like the keep the microcode for the E2160.

    I would like to get either the E5450 or the E5430.

    Also can you tell me what bios settings I need to make in the bios for this to work?

    Thank you.

  • Zach June 1, 201811:29 pm

    Confirmed this mod works on a Foxconn g41s-k motherboard with a L5420 Xeon. This Motherboard has a Max tdp rating of 65watts. Its not just plug and play though you will have to install a modded bios to bypass the CPU Max tdp warning screen. I was fortunate to have found one with the proper microcodes added as well.

    here is the link.

    This mod should also work on the g41s motherboard as well.

  • dev893 June 3, 201812:20 am

    So I have the CPU installed and first boot it works fine then if I reboot for any reason it freezes on the windows 10 boot screen, I’ve got the updated BIOS with microcodes, I modded the socket and added a sticker to the CPU I had to put the C2D e8400 back in, is it possible it’s a bad CPU?

  • Andrew June 6, 20186:58 pm


    I have P5B-MX mainboard which supports upto Q6600 Core 2 Quad CPU.

    I’ve got Xeon E5405 CPU (4 Cores 12MB cache, 2GHz, 1333 MHz FSB, 80W) for BIOS modification

    0. attached LGA 771 to LGA 775 adaptor to the CPU
    1. downloaded P5B-MX BIOS ROM file
    2. deleted support of Intel D and Intel 4 CPUs microcode
    3. injected suggested microcode for CPUIDs 1067a/10676/10677
    4. programmed P5B-MX mainboard with resulting BIOS
    5. attempted to boot the computer with Xeon E5405 and boot failed

    Did I make any mistake? Is there a reason why P5B-MX refuses to boot with Xenon E5405?
    NOTE: P5B-MX, FSB 533/800/1066(o.c)MHz, THD 130W

    I have put original E2200 CPU back in P5B-MX mainboard and the computer boots fine.

    Modified Xeon E5405 works fine in HP Vostro 220s computer without any issues (run Knoppix for a day).

    Thank you,

  • Sushil June 20, 20185:44 am

    I have ASUS P5G41C-M LX motherboard which booted perfectly fine with Xeon x5450 with the help of this mod.Before adding the cpuid patches, i was able to boot up the system with windows 7 but the system didn’t boot with Windows 10 x64 bit. After using the modded bios the system is working perfectly fine so far.I have also added Dell Slic 2.1 for Windows 7,so i just hope it would be useful for someone else.

    ASUS P5G41C-M LX Modded Bios:https://drive.google.com/file/d/1pX41QZvNR7ITQzIudbzmf8QgOdi7AKue/view?usp=sharing

  • sprit June 21, 201812:55 pm

    i have a asrock g41c-gs r2.0 will a x5460 work on my motherboard if i already have a q9400


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.