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 $11 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

2,164 Responses

  • Alessandro November 21, 20172:49 am

    4Core1600Twins-p35 xeon E5410 works fine

  • axtrako November 27, 20174:14 pm

    X5470 @3.500 with GA-P35-DS3L. Totally stable
    Stress max temp:68º
    with Artic Freeze pro 7, waiting to buy water cooling AIO to try 4Ghz.
    Any recomendation for a nice AIO water cooling compatible with 775 socket?

  • John November 28, 201711:14 am

    E5450 C0
    Works stable, had to update bios with microcodes, because of constant error at startup, yet worked 3.0 ghz without bios update.
    MB reports wrong cpu temperature, +15C actual temp.
    Max 52C temp at full load

  • Fazekas-Gyermán Róbert December 1, 20173:14 am


    MS-7528 MSI G31M3-F-2 Xeon 5260 C0 and E5410 (C)

    Intel DG41RQ X3323 and works with E5410 CO


  • gunter December 1, 20171:35 pm

    добрый вечер у меня материнская плата p5p41td хочу поставить процессор Intel Xeon X5470 пойдет ли на мою плату???. второй вопрос нужна ли прошивка bios ??то какая??

    • Vincent12 December 4, 20172:38 pm

      добрый вечер у меня материнская плата p5p41td хочу поставить процессор Intel Xeon X5470 пойдет ли на мою плату???. второй вопрос нужна ли прошивка bios ??то какая??

      translated via Google-translate:
      good evening I have a motherboard p5p41td I want to put the Intel Xeon processor X5470 will it go to my board ???. The second question is whether the firmware bios ?? then what ??

      Your Asus P5P41TD motherboard has P41 chipset (so fortunately no X38/X48/Q45/Q43/Q35/Q33 chipset), so it does even support the Xeon x54xx series, and the x33xx Xeons series anyway. :-)

      It also supports higher TDP CPUs like QX9650. So your Xeon X5470 should work,

      But perhaps there is some trouble you might run into it (only if you have very very bad luck):

      I’ve got a (bit) similar board – Asus P5P4(3)TD-Pro with P43 chipset.
      For some reason it doesn’t want to boot most of the times with my Xeon X5470 (E0, CPUID 1067A – (its CPU-VID is 1.250 V = here 1.250 V is the recommended minimum Vcore voltage for stable running). My processor sample has not any telerance running it below the 1.25Vcore

      The P5P43TD Pro Bios sets lower Vcore by standard than the specified VID and then it doesn’t boot with the X5470 most of the times, and when it does I have to hurry very fast to manually raise the Vcore to 1.25 V, Saving and applying the BIOS changes before it crashes in BIOS.
      THis procedure I’d have to do always after a BIOS reset, or when the CMOS battery is empty.

      After raising the Vcore in BIOS to 1.25V X5470 works stable but with my P5P43TD Pro it detects only two (2) cores, even though also microcode update done already with proper microcodes.

      However with my Xeon E5450 (also E0, CPUID 1067A) my P5P43TD Pro it detects all cores and it runs stable also by standard BIOS settings.

      This is just some experience I had with my P5P43 TD Pro, if you should run into this trouble, but I’m optimistic your board won’t have these issues. My Asus P5P43TD Pro board seems to have been used heavily from the previous owner, so maybe it’s a bit damaged that could be the reason why it doesn’t work properly with my X5470.

      Your board most certainly uses AMI American Megatrends BIOS, so you’d need MMtool for Microcode modding.
      Be sure use the latest BIOS and update it with the proper microcodes, for VT-x Speedstep and SSE4.1to be able to install Win 8.1 and Win 10 via that machine.

      My Asus P5P453 TD Pro uses AMI-BIOS as all my other LGA 775 Asus motherboards.

      You find MMTool BIOS mod tool here at delidded.com
      and which microcodes you need

      I f you still unsure which microcodes you need, please ask back :-)

      Important notice: Asus P5P43TD boards and P5P41TD support a maximum FSB of 333MHz, they have not many CPU power phases, so not suitable for overclocking! So I suppose you won’t get any more than standard 3.33 GHz with the X5470.

  • Sergio Camacho Rico December 1, 20173:59 pm

    Xeon X5460 (SLBBA, E0 Core stepping) installed successfully on ASUS P5Q-EM (G45 / ICH10 1600FSB).
    BIOS 2203+ Xeon Microcode.
    Just following the instructions everything perfect!
    Don’t forget doing the CMOS RESET before 1st start!!

    • Vincent12 December 4, 20176:00 pm


      have an Asus P5Q-EM myself. and BIOS 2203. Works well with L5430 at standard clock.

      Nonetheless the Asus P5Q-EM seems bad for overclocking, doesn’t have many CPU power phases. Already tested decent overclocking with not so good results.
      Raising CPU Vcore and NB-voltage fair enough, other critical settings set manually at conservative values etc.

      Well it boots fine with FSB400, but always after 46 hours I get rounding errors in Prime95 at one random core, (“rounding 0.4.. less than expected 0.5” s.th.l ike that) tested with BSEL FSB-pad mod (for standard 100 MHz PCIe frequency allowance)

      Prime95 itself doesn’t crash, running further with the other 3 cores only.
      Setting FSB to 399 MHz to get 100MHz PCIe frequency by BIOS setting also doesn’t help to get rid of the rounding error when overclocking.

      “Only” at standard clock (FSB 333) Prime95 runs through fine without any errors on the P5Q-EM, tested with L5430.

      • Sergio Camacho Rico December 5, 201710:30 am

        Hi Vincent,

        I’m not into OC right now. AFAIK the P5Q series have some basic OC features but probably as you point not the best out there.

        In my case I like to run the x5460 on stock speed and low consumption. But it seems to be asking for a little ride…

  • Владимир December 2, 201712:34 pm

    MSI g31tm-p35 если поставить xeon x5260 будет ли работать ПЛИЗЗЗЗЗ

  • Владимир December 2, 20171:01 pm

    поставил xeon x5260 биус его увидел но винда 7 зависает при загруске

  • nono December 2, 20174:05 pm

    Hi guys
    I ordered few 771 xeons from China and I tested them against my motherboards, so:

    * ASUS P5WDG2 WS Professional
    Bios 905 + microcodes added
    Chipset: 975x
    All xeons worked: E5450, L5408, L5320, X3230

    * P5KLP-AM
    Bios 603 + microcodes added
    Chipset: G31
    All xeons worked: E5450, L5408, L5320, X3230

    * ASUS P5Q-E
    Bios 2101 + microcodes added
    Chipset: P45
    All xeons worked: E5450, L5408, L5320, X3230
    Rem: xeons 54xx weren’t stable until I disable the C-STATE option
    Rem2: 54xx xeons’ stock temperature seems very high compared to previous core quad cpu, even heavily OC.

    * intel server S3000AH
    Bios R54
    Chipset: Intel 3000
    Only xeon x3230 works…
    Rem: I didn’t find a way to add microcodes. Anyway, this MB even doesn’t post with non officialy supported cpu.

    …And I kept the better for the end:

    * P5PE-VM
    Bios 1501 + microcodes added
    Chipset: 865G
    xeons worked: E5450, L5408, L5320
    Rem: I didn’t dare to put the x3230 as its TDP seems very high and this MB has quite weak power stage (cheap capacitors)

    I LOVE this MB, 24H/24H home server during 5 years, “test” computer since 4 years, so old but still alive after so many tortures, bought 17€ second hand…
    You won’t believe this little MB with AGP+DDR Ram could run 54xx/53xx xeons, but it does, it works like a charm.
    I tried also pentium and core2 E5xxx, E6xxx, E4xxx, E7xxx, E8xxx, Celeron 1xxx, 3xxx, 4×0: ALL WORK!
    Of course, maximum FSB is 1066 (and it’s already OC!), so don’t expect to run 1333 FSB cpus at stock speed.

    • nono December 2, 20174:07 pm

      P5KLP-AM & P5PE-VM are ASUS motherboards, sorry I forgot to write it.

    • Vincent12 December 6, 20175:26 pm

      About this C-State thing, all my different motherboards from Asus and Asrock don’t boot into Linux, and not into Windows, when I enable C-State, (still not tested with Gigabyte boards)
      Afaik even with my Q9550S it works not stable when enabling C-State technology.
      And afaik, C-State technology is disabled anyways on the standard BIOS settings.

      Not to confuse with C1E Support, which works fine with all my different computer brand, also with Xeon etc.

      • nono December 10, 201712:57 pm

        Nice to known Vincent!
        I confirm, I disabled C-STATE bios’ option in order to prevent Linux from weird slowness. I didn’t mix with C1E.
        C-STATE option enabled works (or useless?) on P5Q-E with previous cpus: q6600 and e6300, even with my “new” L5320.

        • Vincent12 December 10, 20176:56 pm

          Well, all my boards it always hangs at the Windows 10 logo at Windows boot with C-State enabled (proper microcodes already added)
          Those Windows circle dot points turning around endless time and not any Windows boot sign, even after 15 minutes.
          When I dsiable C-State suddenly Windows 10 boots fine normally.

          And Linux also is either slow, doesn’t boot or hangs with C-State on all my 775 boards, even with Xeon-771/C2Q-775 computers.

          In can exclude my PSUs. They even support Haswell lower C-States.

          Using one Coolermaster G650M ATX-Bronze, one G550M ATX-90plus-Bronze, two V550S ATX Plus-Gold (one of this got defective after 1 Jahr though, condition was new at purchase (no retoure) and PSU still looked as new :D, got one V550 ATX-PLus Gold as warranty replacement, and bought two Coolermaster V650S ATX-Gold on ebay at reduced price.

    • hyan December 7, 201712:35 am

      asus p5ql pro with x5482 C0 or EO, any possiblity ,i have psu 400watts, bios 1004 year 2009,2 gb ram,no interest in over clocking,this is actuly a refurbished motherboard 8 months old now,once was shut down n dint start but after cleaning it started n runing now for 3 days,i am afraid to do bench test.jus want to know whether this xeon cpu wil work ,shud i do any mod or any problem wil come in long run to other parts of mobo….pls tell thanks.

  • Ivan December 3, 201710:15 pm

    I have an Asus p5q3 deluxe!
    What do I need in order for this mod to work?
    I’m searching for for the x5470 but if there’s a better choice than that let me know.
    Thanks in advance!

    • Vincent12 December 6, 20177:13 pm

      You need to cut off the two plastic tabs around the socket (carefully without breaking and without bending any nearby socket pins.
      This is neccessary because for the 771-Xeon-CPUs the notches are turned at 90 degrees compared to the 775 CPUs, and the Xeons don’t fit in when the two socket plastic tabs are not removed.

      =>see description and 2nd picture

      After tabs removed you need to attach the 771-775 Adapter.
      =>See picture 1

      You need to add Xeon microcode to BIOS for the full CPU instrcutions support of the Xeon CPU.
      Asus P5Q3 Deluxe uses Amercian Megatrends (AMI) -BIOS, so you need MMTool AMI Modding tool

      The MMTool download, and which microcode/s you need, you find there.

      X5470: CPUID: 1067A (hex)

      Some tip for safer cutting of the plastic tabs:
      I’m using a box cutter to cut off the two plastic tabs (I prefer not the biggest box cutter, I’d say with a circa 5-7mm/10 mm wide blade, and max 0.1-0.4 Millimeters thick).
      I find this is helpful, so there’s a bit more safe distance between knife and socket pins.

      And when the blade is thin enough, it might even fit into the gap of the first pin-row of the 2nd more difficult plastic side of the socket if you should slipp off in paarallel occaisonally.
      This rescued me, my thin box cutter blade fits in between this gap.+
      When I slipped into this gap with a part of the blade end unwanted, I just reached the gap, and didn’t bend nor break any pin at the pin row next to it etc :-)

      It is strongly recommended to use both hands holding the cutter.
      It’s for if you have shaky hands, and you can retain slipping off or at least reduce the slipping off,
      both hands together rescued me several times from touching any socket pin when I slipped off.

      And this blade size itself is still stable enough for those forces using here.

      However with my box cutter the 5-10mm blade is not optimally fixed when I don’t prepare it (the blade always waggles a bit forward and backward even when attempting only a few pressure when trying to cut off the plastic tabs).
      This slipping is dangerous and can potentially reach nearby socket pins.

      To solve this issue I’m fixing the box cutter e.g. with cellotape with tape windings on each side of the slider (where you set the blade length etc)

      Don’t forget to set the correct blade length by pushing the slider length, (NO need to shorten the blade itself by breaking off a segment) (good experience with 1-2 cm max blade length) before fixing slider+blade.

      I use at least 6-8 cellotape windings on both sides of the slider.
      It doesn’t hurt if the tape winding side is close and overlapping to the slider going a bit under the slider in the gap there.
      This fixes the slider more reliable. Have had very good experience with this method.

      And I’m fixing the motherboard with duck tape on a table.
      Then I start with the easiest plastic tab next to the CPU alignment triangle.
      First I use very few pressure, just to cut a 0.5 – 1.0 mm deep gap at the place where I cut off the plastic tab. This can take 10 Minutes. Just don’t be in a hurry.
      After that when there is a 1 mm gap in the plastic tab, you can cut from within inside the plastic, this protects the knife a bit from slipping off :-)

      When the gap at the cut place of the plastic tap is a bit deeper (minnimum 1 mm Millimeters deep) you can carefully increase presseure a bit, and cutting off the plastic tap goes faster.
      I’m turning the motherboards at 180 degress from times to times every few minutes so that the gap is constantly deep on both sides and not inclined which could provoke more to slipp off.
      If you cat a plastic tab from only one side it is inclined, as you hold the cutter inclined, so cutting the same tab from two directions by rotating the motherboard at 180 degrees helps.
      The ducktape still holds when reusing it when turning the mobo.

      • Ivan December 10, 20171:22 am

        Thank you so much!
        I cut the plastic tabs with a xacto knife previously heated to made ot even easier. I downloaded the microcodes for x5492 and x5470 and the MMtool for my bios. Now I’m debating between those two processor tho. I’m currently using a q9550 @ 3.40 GHz so what of those two processor mentioned above do you recommen me?

        • Vincent12 December 10, 20174:23 am

          Am 10.12.2017 um 07:25 schrieb info@delidded.com:
          > Thank you so much!
          > I cut the plastic tabs with a xacto knife previously heated to made ot even easier. I downloaded the microcodes for x5492 and x5470 and the MMtool for my bios. Now I’m debating between those two processor tho. I’m currently using a q9550 @ 3.40 GHz so what of those two processor mentioned above do you recommen me?

          Well it depends, if those about 20Watts more power consumption from X5492 at full load doesn matter to you, and if the X5492 are clearly quite cheaper, and you don’t want to overclock for sure, also in the future, you can choose the X5492.

          If you want to overclock, and the price for X5470 is not much higher than X5492, I’d recommend you a Xeon X5470 (SLBBF), and the X5470 is very good for overclocking, better than the X5492.

          And if the X5492 is more expensive than X5470, for sure you should take the X5470 anyway. :-)

          Maximum power dissipation ? 157.75 Watt; 141.82 Watt (sustained)
          Thermal Design Power ? 120 Watt

          Maximum power dissipation: 182.8 Watt; 162.81 Watt (sustained)
          Thermal Design Power ? 150 Watt

          Another CPU which is very interesting is the Xeon X3380 (LGA77(5) , SLGPG , 3.16GHz, 9.5 Multi , FSB333, TDP 80Watt only!!).
          Onfortunately sold out already on ebay afaik.

          The technical reason why X5470 better than X5492:

          The X5492 just achives 3,4 GHz with an already “high” FSB of 400MHz compared to the X5470 (3.33 GHz already with just FSB 333)
          (So there is NOT much tolerance for overclocking the FSB on an X5492, At higher FSB400 there’s not so much room up for longer-term-reliability, due to higher CPU voltages, higher Vcores used there, and the high TDPs etc)

          The X5470 has a Multiplier of 10* (highes Multiplier of the 45nm Xeons) =>10 * FSB333 MHz =>3333MHz =>3.333 GHz
          When you overclock the FSB of the X5470 to an FSB400 you get 4000MHz clock easily =>FSB400 (overclocked) * 10 =4000 MHz =>4GHz

          Though the X5492 has only 8.5* Multiplier =>8.5* FSB400 MHz =>3400MHz =>3.400 GHz
          For the X5492 you’d need FSB470.588 MHz to reach 4Ghz =>470.6 .. *8.5 =>4000MHz =>4GHz

          So 470.588 MHz FSB is a high FSB. And I can see on my boards that the Northbridge gets quite a bit hotter when overclocking FSB from 333 to 400MHz. So 470MHz FSB is just even quite worse.

          The Xeons have a fixed Multiplier (locked Multiplier). You can overclock them only through the FSB.
          You CANNOT overclock Xeons through Multiplier(!)
          So even when the Multiplier is locked, for overclocking, it is an advantage to take a Xeon model type with as much high Multiplier standardly as possible.

          And also all Xeons X5470 have the newer E0-Stepping, the same like all the X5492.

          Your Asus P5Q3 Deluxe is very good for overclocking. It manages FSB 400 well according to overclockers.
          And the Xeon X5470 manages an FSB 400 very well.
          In fact I’d guess all 45nm FSB 333MHz Xeons do manage FSB 400 pretty well, and FSB400 is just 6/5 (*1.2) of FSB333
          The issue is rather with the board, it must also support good overclocking (enough CPU power phases)
          4 CPU Power phases are not always annugh. With 8 phases or at least 6 CPU power phases you are on more safer side.
          I think the Asus P5Q3 Deluxe has eight.

          4*4GByte DDR3 at 800MHz/DDR3-1600 without problem if you have the proper RAM manufacturer.
          I have similar board Asus P5Q3 (non-Deluxe), also P45 with DDR3. This board manages FSB 400 well too, but it allows only 800MHz/DDR3-1600 DDR3-RAM in the two Orange DIMM-Slots, so max 2 * 4-GbyteDIMMS =(8 GByte) at DDR3-1600.
          Samsung RAM was the only brand which works totally perfect on my Asus P5Q3. I have 4*4 GByte Samsung DDR3-(1333) M378B5273(C)H0-CH9 in that board.
          The Samsung M378B5273(D)H0-CH9 DDR3-1333 works well too, tested.
          I’ve had had good experince with Samsung RAM.

          And I’d recommend you Samsung 4GByte DIMM/(s) DDR3-1600 M378B5273(C)H0-C(K0) or M378B5273(D)H0-C(K0) DDR-1600.

          If you want to overclock and if you want 4 * 4GByte DIMMS (=16 GByte).
          The P5Q3 Deluxe manages DDR-1600 in all DIMM slots.

          You can still underclock them to 1333 MHz, this is in the JEDEC standard if you don’t want to overclock.
          Samsung RAM was the only RAM that works reliably in my P5Q3 at full 4*DIMMS placement, which hates Corsair. Other brands not tested yet.


          • Vincent12 December 10, 20174:43 am


            I have to add. I you have a Q9550 at 3.4 Ghz in your Asus P5Q3 Deluxe, it’s not really worth at all trying to upgrade to another CPU, which might be a few percentages faster.

            Only if you want to overclock an X5470 to 5GHz at FSB500.
            But you’ll need so much Vcore voltage there then, for sure more than maximum 1.3625 or 1.35V Vcore commendation from Intel.
            The CPU will suffer elctromigration, needing more and more Vcore to operate stable even at standard.
            Your X5470 will be dead in the water then soon at 5GHz, and the Mainboard-Northbridgte, too.

            And I’d find it unfair if I’d would sell such broken CPU to buyers via ebay ;-)

          • Ivan December 27, 20176:41 pm

            I’m sorry for the late reply but with holidays around the corner I was pretty busy!
            I found a x5470 at a very good price and in the states so I didn’t hesitate and went for it. I built this computer back in 2008 or so. This is just for fun and I just want to see which one can handle better a GTX 1060 without crazy bottleneck.
            My memories are OCZ’s ! They are DDR3, stock they run @ 1600 mhz but I have them oce’d to 1800 mhz.
            I can’t keep them stable @ 2 ghz and the q9550 runs stable @ 3.84 ghz at the most. Problem is that I only have 4gb of RAM but I think it should be plenty enough.
            Thanks for letting me know that differences between those two processors, that was awesome!

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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.