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

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2,108 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 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 $14 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

2,108 Responses

  • DaniV March 28, 201811:21 am

    Hello, I buyed intel xeon E5440 SLBBJ (E0) from aliexpress for my Pegatron IPMEL-AE motherboard with G41 chip but couldn’t make it work properly.
    First i tried to install it without microcode update since i have G41 chipset but it just got stucked on the initial BIOS screen and didn’t enter neither the BIOS or windows.
    Then i updated the microcode via afudos and (after removing the battery of the BIOS and reset it to default) was able to enter the BIOS, wich recognised the processor but once i tried to enter the system the loading screen was laggy and after a while (MUCH longer than it takes to boot the system) it showed me a blue screen with the error code “DPC WHATCHDOG VIOLATION” wich seems to be probably hardware incompatibility.
    I saw on some comments that some processors doesn’t work with E0 stepping but they do with C0. Does anyone with a similar motherboard know if it can be related to that or if there is any solution?
    I will be very thanfull with any help you can provide me :).

    Reply
  • OliKa March 29, 20185:28 am

    Hi,

    I tried mods with three Motherboards lately using XEON E5450 SLBBM (Stepping A Revision E0).
    Hopefully I can help updating the motherboard list.
    On all the motherboards I used microcode upgdated bioses from http://genius239239.myweb.hinet.net/771/

    1. ASUS P5N7A-VM

    – “Intel C-State tech” MUST be disabled!!!
    – C1E can remain enabled!
    – stable for more than 24 hours

    When enabling C-state booting Win10 and Linux will be slowed down extremely (like 20 minutes or so to login)

    2. DFI LANPARTY JR GF9400-T2RS

    – works like a charme, all available C-state settings enabled
    – stable for more than 24 hours

    3. Gigabyte GA-E7AUM-DS2H

    – very unstable!
    – playing with c-state settings doesn’t improve stability
    – sudden hard restarts (without bluescreen) between running time of 15 min. to max. 3 hours
    – checked with 2 XEON CPUs – same result
    – works well with Core2Duo E8400, so the motherboard itself is most likely okay
    – failed with this XEON E5450 E0

    Reply
  • GRX April 1, 20182:12 am

    Have had this working for a year no issues in my Gigabyte Motherboard (previously listed).
    However, someone trying this may want to be careful about temps. I installed this E5450 in my machine just using the original Core Duo heatsink fan and some new arctic silver.

    According to both the hardware temp monitors I have installed I’m idling at 58C on the cores and SURGING up to 95C at load. CPU reading is at 42C under load.

    If this core reading is accurate, I’m surprised the CPU hasn’t exploded. But, unless a replacement heatsink and fan is really Cheap, it isn’t worth it to invest anything else into an obsolete system (just the CPU swap is getting questionable at this point).

    Just thought I’d throw that out there. Apparently, you can’t take it for granted that you can run this Quad Core even at stock at a reasonable temp using Core Duo cooling.

    Reply
    • GRX April 5, 20187:28 pm

      I think this is resolved. Some of the issue ended up being that the temps were reported somewhat inaccurately high. Although, even discounting that, the temps were still way too high.

      the main issue ended up being the Intel heatsink and fan. At least one of the plastic pins which is supposed to mount it to the board had broken off, allowing the heatsink to ride up on a corner.

      This Intel cooler is a real POS. I ended up removing the motherboard, ripped the pins out of the heatsink/fan and bolted it to the board using thin bolts, nuts and thick rubber gasket washers.

      After, temps at idle have dropped to around 40C and around 60C at max.

      That should do it- for non-overclock

      Reply
  • ShohS April 1, 20185:19 am

    MSI g41m-sp20 works with E5450 (E0) (xeon microcode applied)
    MSI p31 neo v2 works with E5430 (C0) (xeon microcode applied)

    Reply
  • Vince April 4, 20184:46 am

    Vostro 220 board with xeon microcode bios update doesn’t boot with an E5472

    Reply
  • Rafael Costa Ferraz April 12, 20183:21 pm

    Hello friends, as I was recommended, I placed the intel xeon 5450 on my motherboard striker extreme chipset 680i, but when I updated the bios of her with the file 771 of this link that I was indicated (http://ideafix.name/stuff/Striker -Extreme.zip)
    My computer does not start ….
    (Note, it does not even start with my old processor)

    Please, friends, I need help …

    Reply
  • Greensmack April 15, 20189:39 am

    Hi,

    I wanted to report that I have an Asus P5W DH Deluxe motherboard running on a Xeon 3370; clocked to 3ghz per core with an FSB set to 300mhz.

    Depending on the video card installed, and if PEG is enabled for the video card, the FSB can go as far as 315mhz before encountering BSODs in windows. (PEG is a PCIe bus performance booster that also can affect any PCIe peripheral cards, too; like SATA or NVMe adapters/controllers for PCIe slots).

    To get the 3370 to work properly, the same bios I had previously was simply reflashed back to the motherboard.

    I did not have to update the microcode of the bios rom itself, although I wouldn’t advise against it; I just wanted to report that the latest public release for the P5W DH Deluxe works with the Xeon 3370; bios messages about the microcode go away if the same bios is reflashed back into CMOS.

    (I just wish 64-bit PCI-X functionality could be introduced the same way!)

    Reply
  • bart April 17, 20185:02 pm

    ASUS P5K-VM works generally with a X5470, but i get during booting the folowing error mesagge:

    ERROR! The CPU Core to Bus ratio or VID configuration has failed!

    will try a stronger Power supply tomorrow…

    Reply
    • bart April 19, 20186:05 pm

      700W Powersupply did not help,
      System is running stable but i do not have the full perfomance (~3900 CPU Mark Score instead of ~4600)

      Microcode update has been processed, BIOS resetted… any hint ?

      Reply
  • JJ April 21, 201811:53 am

    Just came here to say that the ASUS P5QL-EM works, seems by the model number it’s the same series as the P5QL-E plus the specs are similar, and the 5450 Xeon that I used is compatible with both motherboards

    Gave a 10 second countdown, flashing microcode update fixed it, the user interface of the bios modding program could be designed better tbh

    Reply
  • Ghetto April 23, 20189:48 pm

    Gigabyte GA-G31M-ES2L rev 2 with bios overclock (1600mhz) and E5472 C0 stepping SLBBH working great, no issues

    Reply
    • Ghetto April 23, 20189:50 pm

      Sorry it’s a SLARN not SLBBH

      Reply

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.