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



If you're looking to extend the life of your LGA 775 system, there's an adapter available now that will let you install faster (and usually cheaper) Intel Xeon processors (LGA 771) into a Core 2 Quad motherboard (LGA 775). These Xeons cost a lot less and are basically identical internally to the high-end Core 2 Quad CPUs.

List of LGA 771 & 775 CPUs + Current Prices

The pages shown below should help with comparing Xeon prices and specifications. The first link has all the LGA 771 and LGA 775 CPUs combined into 1 table (sorted by price), and the others are the original uncombined pages.

Where can I get an adapter?

Here's a current list of eBay sellers (sorted by price). The sellers are located all over the world, so you should be able to find one that's close to you, and most of them will also ship worldwide.

Why would you want to do this?

Xeons are usually MUCH cheaper

For example, the Xeon E5450 is equivalent to a 3.0 GHz Core 2 Quad Q9650, and it currently costs about $6 on eBay (usually much less than the Q9650).

Other good deals on LGA 771 Xeons include:

For detailed specs on all of the Xeons and a full list of current prices, take a look at this page.

Xeons also typically overclock better

Additionally, if you’re interested in overclocking (making the cpu go faster than its default speed), Xeon processors are usually made from the best silicon, so you can typically achieve higher overclocks with them.

Someone that recently did this mod successfully overclocked a Xeon X5470 from 3.33 GHz to 4.5 GHz on an ASUS P5Q PRO motherboard, so you can achieve really good results with these Xeons.

How does the adapter work?

The adapter is basically an electronic circuit on a sticker, and you place it on the Xeon processor (as shown in the picture below). This switches two of the pads on the bottom of the Xeon to make it compatible with a Core 2 Quad motherboard.

Xeons that are compatible with this adapter

This adapter is only compatible with LGA 771 Xeon processors. If you're unsure what LGA 771 means, it's the name of the CPU socket used in some Xeon motherboards. And in comparison, LGA 775 is the name of the socket used in Core 2 Duo/Quad motherboards.

LGA 771 to 775 Adapter

Minor modification to the LGA 775 socket is also required

If you look at the LGA 775 socket in the picture below, you'll notice two tabs are circled in red. These tabs are there to stop you from installing a non-LGA 775 processor, and they'll need to be fully removed before you can install an LGA 771 cpu.

The tabs are pretty easy to remove if you have a sharp utility knife or box cutter (just be careful not to damage or bend any of the socket pins near the tabs).

Important: Make sure that you fully cut off each of these tabs. If they're not fully cut off, the processor may not align or seat correctly in the socket, which will stop it from making contact with all of the pins. If this happens, your system will likely fail to boot.

Once the tabs are cut off, you can use tweezers to safely remove the pieces from the socket.

The socket will then support LGA 771 or 775 processors (you can still reinstall your old processor if you ever need to).

Tabs to removed from the LGA 775 socket

2,386 Responses

  • rememberve February 10, 20198:45 am

    Xeon X5460 (E0 stepping) works great on Dell Optiplex 360 (0T656F motherboard model). But needed to update BIOS to A07, and use utility like SpeedFan to more active fan work. With good thermal compound heat is near 65 C degree under stress test. Daily use – 34-38 C degree.

  • HC February 14, 20192:24 am

    Hi, The Asrock G31M-S has two versions, bouth support Q6600(B3) max TDP 105, in your list you have X5450 TDP 120 worked on this Mobo, How is this possible if the TDPs are very different, how about the compatibility.
    Please let my now if your configuration is Right. I plan to buy a xeon for that motherboard and I need to be sure. FSB no problem although I think that a 1600 FSB xeon would be better like Xeon E5472. Thanks.

  • LEO February 17, 20197:24 am

    FUNCIONA ESTE MOD EN UNA gigabyte g31m-es2c

  • Denis Kleinschmidt February 25, 20197:18 am

    Guten Tag, das Gigabyte EP45T-EXTREME + X5492 + OCZ Revodrive 3 + HD6990 läuft seit Jahren sehr gut. Danke für die Anleitungen.

  • Valera February 27, 201912:34 am

    Материнская плата Asrock G43 TwinFullHD работает с процессором Xeon E5410 степпинг E0, Так же работал X5460 степпинг E0. А вот процессор E5440 со степпингом C0 не запустился. Версия BIOS материнской платы 1.9 модифицированная с последними микрокодами 2010 года. Кстати этот Xeon E5440 мне не удалось запустить на сервере HP DL380 G5. Сразу при загрузке сервера вылетает BSOD.

  • dude March 2, 20191:22 am

    Hi, thanks for this post, this is the greatest post i’ve seen for a while. I’ll buy a xeon l5408 and try to overclock it, my pc is hp dx2400, it’s in the supported list, in the list it says it supports l5420 will it support l5408 and do i need a microcode update ? Also current bios won’t let any overclock settings, is there a way to unlock overclock settings ? Thanks.

  • ninkeon58 March 2, 20197:42 pm

    Got a Xeon X5450 (C0) working nicely on an Asus Striker II Formula (an nForce 780i board).

    However, it needed to have all C-States turned off in order for it to boot correctly from a cold start or to restart at all. Otherwise it seems to get stuck before POST (gives random beep code errors). Doesn’t appear to be related to clock speed or memory configuration either.

  • cybercryme March 4, 20197:43 pm

    Не нашел свою мать в списке, Gigabyte GA P35 S3L, воткнётся ли в неё e5450 (SLBBM) , если да то есть у кого файлы для прошивки?

  • Vlado March 6, 20192:02 pm

    Hello people,does someone know Can I put Cpu Intel X5460 Quad into the Acer Aspire M7711 lga 775.And how to update Bios if needed…Thanks

  • Marco March 15, 20194:50 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?


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.