LGA 771 Xeon Microcode – How to MOD Your BIOS



In this guide, we'll cover how to add the LGA 771 Xeon microcode to your BIOS. This is sometimes necessary for people doing the LGA 771 to 775 MOD.

How will updating the microcode help?

It can restore missing CPU instructions

If you did the LGA 771 to 775 MOD and notice missing CPU instructions (such as Speedstep, SSE 4.1, VT-x, or CompareExchange128) adding the Xeon microcode will usually restore that functionality.

It can also improve system stability

Microcode updates usually fix bugs or add new features, so by updating the microcode, you can sometimes make your system more stable.

LGA 771 Xeon microcode guides

Important: Make sure you do a FULL BIOS reset after updating your microcode.

If you have an Award, Phoenix, or AMI BIOS, the guides shown below should cover everything you need to know to add the LGA 771 Xeon microcode to your BIOS.

How can I tell what type of BIOS I have?

You may see the BIOS type when you turn on your computer or enter the BIOS. If you don't, you can use a program called CPU-Z to look this up (it should be listed as BIOS Brand in the Mainboard tab).

Note: AMI is short for American Megatrends Inc., so you may also see it listed the long way.

LGA 771 Xeon microcode files

Note: You don't need to download any of these files if you're using one of the guides shown above (they already have the correct microcode files).

  • Desktop LGA 771 and LGA 775 microcode
    • If you're trying to add LGA 771 Xeon support to an LGA 775 motherboard, this is the recommended file to download. It will allow you to not only add the LGA 771 Xeon microcode to your BIOS, but you can also update your processor's similar LGA 775 microcode (which is probably a good idea).
    • Contains microcode for all Core 2 Duo and later desktop processors (no Pentium 4 or mobile support).
    • Also contains the LGA 771 microcode shown below.
  • LGA 771 microcode

When you unzip one of these files, you'll see a bunch of individual microcode files that have filenames like this:


Here's what the different parts of the filename mean:

  • cpu0001067a - 1067A is the CPUID that is supported by this microcode
  • plat00000044 - plat is short for platform. This tells which sockets are supported by the microcode.
    • LGA 771 microcodes have a 4, 40, or 44 in this section
    • Desktop LGA 775 has a 1, 10, or 11
    • And for mobile LGA 775 it's a 20, 80, or A0
  • ver00000a0b - a0b is the version number
  • date20100928 - 2010-09-28 is the date the microcode was last updated

Which microcode files should I set aside?

You'll want to set aside all of the microcode files with your processor's CPUID (how to get the CPUID). There should be at least one of these for each platform, and you should go ahead and update the microcode for all of the platforms that you want your motherboard to support.

Note: If your CPUID ends in an "h" and you don't see microcode with an "h" on the end, just ignore the "h" because it isn't actually part part of the CPUID. That just means it's a hexadecimal number.


So for our E5450 (E0 stepping SLBBM) with a CPUID of 1067A, here are the LGA 775 and LGA 771 microcode files with a CPUID of 1067A:

  • cpu0001067a_plat00000011_ver00000a0b_date20100928.bin
  • cpu0001067a_plat00000044_ver00000a0b_date20100928.bin

If you have that processor and want to add the LGA 771 microcode and update LGA 775 microcode (which is recommended), you'd want to set aside both of these files.

What to do if you don't have an Award, AMI, or Phoenix BIOS

Insyde BIOSes

If you have an Insyde BIOS, there's a more advanced guide on manually hex editting a BIOS to add microcode. It is available here.

Intel BIOSes

We don't currently know of any microcode updating guides for Intel BIOSes. We've also heard that Intel may be using a secure checksum to prevent people from modifying them. If this is the case, it would prevent the manual hex editing method used for Insyde BIOSes.

Dell BIOSes

Dell often makes their BIOS updates available in an .EXE file that cannot be extracted by regular unzipping programs, so you'll need to use the trick shown below to extract it.

How to extract the BIOS ROM file from a Dell .EXE file

You can extract the actual BIOS from a Dell .EXE file with the following command:

DellBiosFilename.exe /writeromfile

This needs to be done from a DOS command prompt window.

Other BIOSes

If you have a different type of BIOS, you may be able to update the microcode by manually hex editing the BIOS. If you're interested in trying that, read the Insyde BIOS modding guide.

You may need to update the microcode in multiple places

If you're hex editing your BIOS to update the microcodes, we've noticed that some BIOSes have the same microcode in multiple places. If that's the case with your BIOS, make sure you update the microcode in all of the locations. Otherwise, it may not work.

Where to go for help

If you have questions about updating an Award, AMI, or Phoenix BIOS, leave a comment at one of the guides mentioned earlier.

If you need help with a different type of BIOS, we recommend asking for help at the following places: bios-mods.com, overclock.net, or forums.mydigitallife.info.

89 Responses

  • Rick May 20, 201711:48 am

    Looking for the bios update with microcodes for lga771 to lga775, Intel DP45SG motherboard. Xeon X5460 Processor. Thanks.

    • serg June 30, 20172:43 pm

      Xeon X5450 work

      • Rick June 30, 20179:51 pm

        Thank you, I did find a way of injecting the microcodes to work. And it works great.

    • Stepa July 23, 20174:29 am

      Try adding the microcode with the “UEFI BIOS Updater” (UBU).

  • freakqnc May 20, 20173:23 pm

    Would it be possible to update microcode on Mac Pro 2,1 Xeon X5365 CPUs to that it could satisfy the new requirements to install Sierra (limits to CPU supporting SSE4.2) Thanks

    • Jesse Kramer July 3, 20179:13 pm

      CPU aren’t Microcode Injectable. Upgrade to a pair of X5460. It will be worth it.

      • freakqnc July 19, 20178:27 pm

        I just tried a pair or X5460 and they did not work. The Mac powers up and nothing happens: screen remains black, no boot. Tried to clear PRAM but seems like the logic board isn’t recognizing the CPUs as no chime can be heard. Did you personally do it? Are there specific steps t be performed in order to have the logic board look for and use the new CPUs? Thanks much!

        • Jesse Kramer July 23, 20171:09 pm

          Try update your EFI First.

          • freakqnc July 24, 201710:32 am

            Thanks Jesse, but I have the latest EFI as according to these info on apple’s page at: https://support.apple.com/en-us/HT201518 there’s no newer version than the one I have installed (update performed a few years back).

            Model Name: Mac Pro (8-core)
            Model Identifier: MacPro2,1
            Boot ROM Version: MP21.007F.B06 (EFI 1.2)
            SMC Version (system): 1.15f3 (SMC 1.1)

            So that it’s not an option. I’ve since returned the CPUs but I might try again if i find more info on how to successfully get the logicboard of the MacPro2,1 to accept the X54xx CPUs.

            Any suggestions welcome :)


        • Vengefulpanda August 5, 20178:44 pm

          I own an X5460 and according to Aida and CPU-Z, only SSE4.1 is supported (I draw this conclusion because in the list of instructions only SSE4.1 is listed in both programs).

          Could this be an explanation for your problems getting this “Sierra” thing to run?

  • 2garikrus May 22, 20171:44 am

    Thank you very much. Very useful information.

  • дмитрий May 31, 20171:53 pm

    привет нужен биос для foxconn g 41 MXP/g41 VZP-V проц. xeon x 5450

  • дмитрий May 31, 20172:02 pm

    привет нужен биос для foxconn g41 MXP/ g41 MXP-V intel xeon x5450

    • Stepa July 25, 20179:14 pm

      Инструкция по редактированию AMI BIOS есть здесь:
      Добавить три файла – работы всего на пять минут

  • Vitor Kringel June 21, 201710:22 pm

    Estou procurando update de microcodes do E5450 para a placa mãe mw- g31t-m7. Obrigado.

    • Anderson July 15, 201712:00 am

      Tá no texto, basta adicionar esses dois:


  • morpha July 3, 20178:18 am

    Looking for modded bios asrock p45 turbo twins and x5460

  • Ankur Kumar JHA July 15, 20178:40 pm

    After I upgrade my ga-g31m es2l with Xeon e5450 it is overheating very much and pc shutdown after 5 sec please tell me what’s the problem. I have cleared CMOS and applied thermal paste but no change at all

    • Stepa July 23, 20174:37 am

      Have you flashed BIOS with microcodes for Xeon?

      • Ankur Kumar JHA July 23, 20174:43 am

        Yes i have but it seems there is same issue. Also I have tried q9650 core 2 quad with my motherboard. It runs very well for 20 days but after that it also start over heating even at70°c at bios and any CPU i use now more that 2.5 GHz get over heated in. Bios can you tell me what’s the problem

        • Stepa July 23, 20174:58 am

          Maybe it is a problem with the power supply? I had a similar problem with the Phenom II X4 (It sounds a bit strange, but after replacing the bloated capacitors CPU temperature decreased).

          • Ankur Kumar JHA July 23, 20177:20 am

            You may be surprised to know that the problem starts after install new PSU(power supply).
            And all other lower CPU like core 2 quad 2.33 GHz works good
            What should I do

  • Hari Fitrianto July 24, 20179:50 am

    I have intel desktop board DG41RQ and have up date BIOS latest version RQG4110H.86A.0017.2011.0322.1523, i bought intel Xeon E5440 @ 2.83 Ghz, with mod jumper on pin which is in processor. My OS system uses Windows 7 Professional 64 bit. I have a problem, that is, my computer can not restart. Can only be shutdown and on again. I tried to update the bios by inserting the LGA 771 microcode, but I can not change it. Can you please help me?

  • Салават July 24, 20175:42 pm

    Здравствуйте у меня вот такая материнская плат аGigabyte GA-945GCM-S2, БИОС обновил однако после замены процессора на Х5450 комп не запускается, подскажите что делать?

    • Stepa July 25, 20173:39 am

      945 чипсет не поддерживает 4 ядра. Для этого проца надо искать более новую материнскую плату.

      • Салават July 25, 20173:00 pm

        Ясно жаль конечно, а не подскажите какую материнку лучше использовать?

        • Stepa July 25, 20175:35 pm

          Подойдет почти любая на чипсете G31/G41/P31/P35/P41/P43/P45. Варианты памяти DDR2 или DDR3 можно выбрать на свое усмотрение. Главное чтобы биос был от Award или AMI чтобы его можно было модифицировать.

          • Салават July 26, 20171:40 pm

            Спс но вот еще один вопрос а модифицируется биос как? Просто скачать или проделать все операции с микрокодами?)

        • Stepa July 26, 20175:44 pm

          Биос можно скачать с сайта производителя и добавить микрокод (или найти готовый модифицированный).

          • Салават July 27, 20172:22 pm

            Ясно спс единственно просьба есть как только подберу материнку можно будет у вас еще проконсультироваться насчет биоса и его модификации?)

          • Stepa July 29, 20178:09 pm

            Если вдруг будут вопросы. Чтобы не захламлять комментарии лучше пишите в л.с. на форуме 4пда или ixbt (ник Stepa_ua).

Leave a Comment