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

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1,875 Comments

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 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 $15 (about $70 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

1,875 Responses

  • José November 7, 201710:44 am

    PC CHIPS P4N7050 V1.0 LGA 775 NVIDIA GeForce 7050 / 630i

    Support CPU: Socket 775 Intel Core 2 Quad/ Core 2 Duo/ Pentium D/ Celeron Processors; FSB 1333/1066 MHz

    Max TDP= ?

    MOD: Intel(R) Xeon(R) CPU X5260 @ 3.33GHz
    CPUID 1067A (SLBAS)

    Working on Windows 10 after update microcodes (before that crash at Windows startup logo screen)

    Thanks for this great mod
    Greetings from Chile

    Reply
  • Al November 7, 20172:31 pm

    Gigabyte 965P-DS4 (rev 1) not supported Q9650 http://www.gigabyte.ru/products/page/mb/ga-965p-ds4_10#support-cpu

    Reply
  • Sam November 9, 20174:31 pm

    Right, so i thought i’d take a bit of a gamble, I had a couple of LGA775 boards knocking about (Gigabyte GA945GM-S2 & Asus P5B-VM) so thought i’d try out this mod to see if i could make either one work with a cheap Xeon.

    I brought an E5420 for about a fiver on ebay, got an adapter, made the mods to the Asus board and stuck the processor in. The computer didn’t post, the fans came on and nothing more. I tried again but this time with the Gigabyte board, this had the same results.

    I then found this website and realised that i probably needed an older Xeon to work with my Asus board, so I spent another couple of quid and got an L5320, this didn’t work in the Asus either to my disappointment but i stuck it in the Gigabyte and it worked! Well…sort of, i’ve managed to get it to recognize the L5320 and first post screen with the options to enter the bios/boot menu/qflash etc, but my problem now is that I can’t get any further. None of my USB keyboards will talk to the board to enter the Bios, i’m stuck at the first screen with the computer waiting for a keyboard entry that I cannot give, any help would be greatly appreciated!!

    Reply
    • J November 9, 20179:05 pm

      Sam,

      A possible option would be to get an old PS/2 keyboard and use it to enter bios. Then enable USB Keyboard support in the Integrated Peripherals section.

      The manual says USB keyboard support is disabled by default.

      Reply
  • J November 9, 20178:56 pm

    I’ve just installed the Xeon X3363 into a Gigabyte GA EG45M DS2H motherboard (F4 unmodified bios). Booted into bios and Windows 7 (64) and everything appears to be working fine.

    Below is some of the CPU-Z report:

    CPU-Z TXT Report
    ————————————————————————-

    Binaries
    ————————————————————————-

    CPU-Z version 1.73.0.×64

    Processors
    ————————————————————————-

    Number of processors 1
    Number of threads 4

    APICs
    ————————————————————————-

    Processor 0
    — Core 0
    — Thread 0 0
    — Core 1
    — Thread 0 1
    — Core 2
    — Thread 0 2
    — Core 3
    — Thread 0 3

    Timers
    ————————————————————————-

    ACPI timer 3.580 MHz
    HPET timer 14.318 MHz
    Perf timer 2.767 MHz
    Sys timer 1.000 KHz

    Processors Information
    ————————————————————————-

    Processor 1 ID = 0
    Number of cores 4 (max 4)
    Number of threads 4 (max 4)
    Name Intel Xeon
    Codename Harpertown
    Specification Intel(R) Xeon(R) CPU X3363 @ 2.83GHz
    Package (platform ID) Socket 771 LGA (0x6)
    CPUID 6.7.A
    Extended CPUID 6.17
    Core Stepping E0
    Technology 45 nm
    Core Speed 2833.0 MHz
    Multiplier x Bus Speed 8.5 x 333.3 MHz
    Rated Bus speed 1333.2 MHz
    Instructions sets MMX, SSE, SSE2, SSE3, SSSE3, EM64T
    L1 Data cache 4 x 32 KBytes, 8-way set associative, 64-byte line size
    L1 Instruction cache 4 x 32 KBytes, 8-way set associative, 64-byte line size
    L2 cache 2 x 6144 KBytes, 24-way set associative, 64-byte line size
    FID/VID Control no

    Temperature 0 43°C (109°F) [0x39] (Core #0)

    Reply
  • rtey31 November 11, 20178:51 am

    E5450 works with Asus P5E-VM HDMI

    Reply
  • Retrorockit November 12, 20172:33 pm

    I came across this Optiplex 360 at Userbenchmark.com. It’s not mine so all I have is what’s there. It’s a120TDP chip running on what’s listed as an Optiplex 360 <95W motherboard. X5460. I assume it's SLANP C0 stepping.
    http://www.userbenchmark.com/UserRun/5586412
    This is a 2 RAM slot MB with a 4GB limit form Dell, and Crucial.com, but some users have it running 8GB RAM with 2X4GB DDR2-800. The non ECC RAM for a Dell Precision T3400 Workstation would be the correct ype. Note 5.8GB free with 2GB GPU, so it is recognized.
    http://www.userbenchmark.com/UserRun/3792336
    Their running a Quadro GPU so it might be an IT expert of some kind.

    Reply
  • wlmthconjr November 13, 20177:10 pm

    The Dell XPS430 information is incorrect. Dell says. QX9650 is supported which is 130WTDP
    http://en.community.dell.com/support-forums/desktop/f/3514/t/19441422

    Also at Tomshardware I have a report of an overclock using a BSEL mod to 1600fsb which the X48 chipset does support ( but maybe not in the Dell BIOS options). So I don’t know how 1600fsb CPUs would act in that computer.

    Reply
  • Дмитрий November 14, 20178:23 am

    asus p5q se x5460 c0
    CPU-Z version 1.61
    Processors
    Number of processors 1
    Number of threads 4
    APICs
    Processor 0
    — Core 0
    — Thread 0 0
    — Core 1
    — Thread 0 1
    — Core 2
    — Thread 0 2
    — Core 3
    — Thread 0 3
    Processors Information
    Processor 1 ID = 0
    Number of cores 4 (max 4)
    Number of threads 4 (max 4)
    Name Intel Xeon X5460
    Codename Harpertown
    Specification Intel(R) Xeon(R) CPU X5460 @ 3.16GHz
    Package (platform ID) Socket 771 LGA (0x6)
    CPUID 6.7.6
    Extended CPUID 6.17
    Core Stepping C0
    Technology 45 nm
    Core Speed 1998.0 MHz
    Multiplier x FSB 6.0 x 333.0 MHz
    Rated Bus speed 1332.0 MHz
    Stock frequency 3166 MHz
    Instructions sets MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, EM64T, VT-x
    L1 Data cache 4 x 32 KBytes, 8-way set associative, 64-byte line size
    L1 Instruction cache 4 x 32 KBytes, 8-way set associative, 64-byte line size
    L2 cache 2 x 6144 KBytes, 24-way set associative, 64-byte line size
    FID/VID Control yes
    FID range 6.0x – 9.5x
    Max VID 1.238 V
    Есть ошибки бсод
    SYSTEM_SERVICE_EXCEPTION 0x0000003В
    IRQL_NOT_LESS_OR_EQUAL 0x0000000A
    The driver is mismanaging system PTEs 0x000000DA
    Как проверить все ли правильно работает?

    Reply

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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.