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

2,431 Responses

  • Kero April 8, 20148:00 am

    Hi, I will try XPS 720 as nForce 680i chipset, I read a details with your guide. Does not supported 45mn XEONs. Few guys succeeded X5460 on it, no issues. Let me know how about it?

    • syn April 8, 20142:02 pm

      Yeah, it works for some and doesn’t work for others with a 680i chipset, so that’s why I mentioned that.

      The 680i chipset doesn’t officially support 45nm quad core cpus (even regular LGA 775), but some motherboard makers unofficially support it, which is why it works for them.

      • Kero April 8, 20147:24 pm

        Thank you for reply as prompt action ! OK, I will try X5470 and X5365 soon. I’m gonna report on this forum.

  • Cichy April 16, 20145:49 am

    Xeon E5410 work fine on Gigabyte GA-EP43-S3L. Now I’m trying run Hyper-V on win2k8 r2, but system show error that cpu have not vt-x but have. Any ideas?

    • syn April 18, 20141:05 am

      Some systems need a bios mod to add the LGA 771 Xeon microcode in order for their system to support VT-X. See this for more details: https://www.delidded.com/lga-771-to-775-adapter/#not-working-as-expected

      • Cichy April 23, 20145:15 am

        I added Xeon microcode to the bios. Hyper-V works fine, but when i run cpu-z program and I don’t see vt-x in instructions form. Generally virtualization works.

        • syn April 23, 20143:49 pm

          If it works, I wouldn’t worry too much about it, but resetting the bios or loading the default bios settings may help.

  • Xantor April 17, 20141:28 pm

    I have Intel Xeon E5450 with this mod in mainboard Gigabyte EP43-DS3 but system see only 2 core not 4 core…

  • Andrey April 18, 20149:13 pm

    Tested x3353 on Intel DG35EC – NOT WORK.
    CPU is successfully work on GYGABYTE gaep45-ud3p, but won’t work on Intel’s board.
    I tried to mod bios, desoldered SPI BIOS flash, reprogrammed by SPIPGM programer, but unlucky.
    Standard quad Q9300 work after reprogramming.
    Will test x5xxx in future.

  • Eddy hvgg April 22, 20146:51 pm

    Hi folks,

    Just updated the F9 Bios for the EP43T UDL3 Rev 1.0 to work with xeon 54xx. use either Q flash in combo with the .F9 file or the @flash / cmd flash with either the F9 or the bin file it does not make a difference only Q flash can be annoying with that sometimes..


    Have Fun !

  • Evgeniy Gergov April 25, 20143:13 am

    E5450 (SLBBM) working on Gigabyte GA-EP35-DS3L with injected microcodes iin bios F6. http://www.datafilehost.com/d/0d669186 . In stock( 3GHz ) no problems, but in OC to 3,6GHz the PC is not stable. Older CPU is E8500 no problems with it in 3,8GHz. I don’t touch voltages and timing setting or enything else in RAM settings…hm . Sorry for poor english

  • Hugo April 26, 20142:05 pm



  • Seonji April 26, 20143:39 pm

    Confirmed working on a Clevo D900C Bios Versoin 6 per HWINFO. CPUID correctly shows the CPU under “specification” as a Xenon e5450 @ 3.0 GHZ BUT says “processor name” is Xenon X3370! All you need is a box cutter knife to mod the socket but be super super careful with the left-hand side plastic pin since it is very close to the CPU socket pins. Spent $40 + $3 for the pin-mod sitcker for the upgrade /no1

  • dino April 26, 201410:22 pm

    Attention ladies and gentlemen, it’s now official, the top of the line Xeon X5492 will run on the Gigabyte
    EP45-UDP3 without any BIOS modification. I just add the adapter, mod the socket 775 and drop in the processor.
    Boot-up posted it as Xeon 3.4 GHZ and ran windows 8.1 without any problems. WOW !!! this processor cost me only $80 on EBAY. I LOVE THIS MOD, THANKS DELIDDED, YOUR INSTRUCTIONS WERE VERY CLEAR AND EXPLICIT.

  • Kastriot April 27, 201410:28 am

    asrock p43de + e5430 @ 3.2GHz working perfect prime64 24h and another Asus p5k deluxe working with e5430 @ 3.6Ghz stable prime64 24h..


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.