Mac Pro CPU Compatibility List

Discussion in 'Mac Pro' started by ActionableMango, Feb 5, 2016.

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  1. ActionableMango, Feb 5, 2016
    Last edited by ActionableMango: Aug 9, 2018

    ActionableMango macrumors G3


    Sep 21, 2010
    Bokkow and I have created a Mac Pro CPU compatibility list. The intent is to cover all relevant and compatible CPU upgrades for all Mac Pros. These are asked about over and over and over again, so I thought it would be nice to have it all in one place.

    Constructive criticism, corrections to errors, pointing out omissions, etc. are all welcome. My intent is, after the content matures, to turn this first post into a wiki so that anyone can maintain it going forward from there.


    • Any and all information here may be incorrect. Use at your own risk.
    • This includes anything offered by Apple (BTO/CTO), third party upgrade guides and commercial services (such as Barefeats, OWC, or xlr8yourmac), or simply individuals claiming personal success in a forum somewhere (such as MacRumors and Netkas). There are probably many unverified CPUs that work, but these are not listed.
    • Memory speed is included in these charts. This is important because in some cases the CPU choice makes a difference.
    • Upgrading to a higher TDP (wattage) processor may increase temperatures and/or fan speed at max load. Macs Fan Control is a popular way to control your Mac's fan and it is available for both OS X and Windows, unlike most Mac fan software.
    • Some used CPUs for sale on Ebay and elsewhere are Intel Engineering Samples. You can read more about these here, but they are basically "beta" versions of the CPU provided to OEMs for testing. These may or may not work in a Mac Pro. In my research at least one person bought an engineering sample that didn't work. Since Intel only loans them out and never sells them, they can also be considered stolen property. People have literally been arrested for selling Intel ES processors on Ebay.
    -Not compatible
    x*Compatible, but see notes about firmware update

    Mac Pro 6,1
    • 128GB maximum RAM
    Ivy-Bridge12 coreDual XeonE5-2697 V22.73.51866130W
    Ivy-Bridge12 coreDual XeonE5-2696 V22.53.31866130W
    Ivy-Bridge12 coreDual XeonE5-2695 V22.43.21866115W
    Ivy-Bridge10 coreDual XeonE5-2690 V23.03.61866130W
    Ivy-Bridge10 coreDual XeonE5-2680 V22.83.61866115W
    Ivy-Bridge8 coreDual XeonE5-2687W V23.44.01866150W
    Ivy-Bridge8 coreDual XeonE5-2667 V23.34.01866130W
    Ivy-Bridge8 coreDual XeonE5-2673 V23.34.01866110W
    Ivy-Bridge8 coreDual XeonE5-1680 V23.03.91866130W
    Ivy-Bridge6 coreDual XeonE5-1660 V23.74.01866130W
    Ivy-Bridge6 coreDual XeonE5-1650 V23.53.91866130W
    Ivy-Bridge4 coreDual XeonE5-1620 V23.73.91866130W

    Mac Pro 5,1 and 4,1
    Xserve 3,1

    • Maximum RAM:
      • 56GB in a single-processor Mac Pro using a single-processor-capable Xeon
      • 64GB in a single-processor Mac Pro using a dual-processor-capable Xeon
      • 160GB in a dual-processor Mac Pro
      • 48GB for a single-processor Xserve
      • 96GB in a dual-processor Xserve
    • For the 4,1 to use Westmere CPUs and run RAM at 1333, it will need the firmware upgrade to 5,1, found here:,852.0.html
    • 5,1 Mac Pros shipped with 1333 RAM even when paired with a Nehalem (1066 only) processor. As shipped, the RAM runs at 1066 because of the CPU. However, if you upgrade to a 1333-capable CPU, your RAM will run at 1333 after an NVRAM reset.
    • Installing a single "Dual Xeon" processor into a single-processor Mac Pro works fine, and actually increases its maximum RAM from 56 to 64GB.
    • Installing just one single-processor-model CPU into a dual-processor Mac Pro technically works, but this causes an error state with the CPU fan going full blast.
    • For two CPUs, you must install two "Dual Xeon" processors. You cannot use two i7 or single Xeon processors.
    • The X#### CPU's tend to have a slightly higher maximum temperature rating than their W#### equivalents.
    • 4,1 dual-processor Mac Pro uses a special, "lidless" CPUs (the single-processor models use normal CPUs). This has a different height than the normal CPUs, so if you upgrade a dual-processor 4,1 Mac Pro with different processors, you need to deal with the height difference. There are several ways to do this:
      • Buy CPUs that someone has already de-lidded.
      • Buy normal CPUs and de-lid them yourself. Here is thread about delidding yourself and here is a video. (And here is a post warning against delidding yourself.)
      • Buy normal CPUs and pay for de-lidding service.
      • Keep the lids on, but be extremely careful about not tightening down the heat sink too much. (If you don't remove the lids it is very easy to tighten down the heat sink screws too much on a CPU that's too large, resulting in damage to the socket, CPU, and/or board.)
      • Other people have kept the lids on, but added washer stacks (of equivalent height to the lid difference) to where the tightening screws go--this is intended to prevent the heat sink from overtightening and causing damage. Here is an informational washer stack thread, and here is a really good post with pictures and a step-by-step procedure.
      • If you keep the lids on, the existing heat pad won't reach the heat sink due to the extra height of the lids. You need to make up for this gap by replacing the heat pad with a thicker pad.
    • The Xserve 3,1 uses lidless CPUs for both single-CPU and double-CPU models. We don't know if the washer-stack trick will work in Xserves as they are physically different than MP, but the other solutions should work.
    • No, the X5687 (3.6GHz quad-core) and the X5698 (4.4GHz dual-core) do not work in Mac Pros. I don't want to list every CPU that doesn't work with a Mac, but these two are asked about often enough to include here, and they've been verified as not working.

    ArchitectureCoresGradeCPU-Model GHzTurboRAMWattMP4,1MP5,1XS3,1
    Westmere6 coreDual XeonX56903.463.731333130Wx*x-
    Westmere6 coreDual XeonX56803.333.601333130Wx*x-
    Westmere6 coreDual XeonX56793.203.601066115Wx*x-
    Westmere6 coreDual XeonX56753.063.46133395Wx*x-
    Westmere6 coreDual XeonX56702.933.33133395Wx*x-
    Westmere6 coreDual XeonX56602.803.20133395Wx*x-
    Westmere6 coreDual XeonX56502.663.06133395Wx*x-
    Westmere6 coreDual XeonE56592.532.80133380Wx*x-
    Westmere6 coreDual XeonE56452.402.67133380Wx*x-
    Westmere6 coreDual XeonL56392.132.67133360Wx*x-
    Gulftown6 coreXeonW36903.463.731333130Wx*x-
    Westmere6 coreXeonW36803.333.601333130Wx*x-
    Westmere6 coreXeonW36703.203.461066130Wx*x-
    Gulftown6 coreConsumeri7 990X3.463.731333130Wx*x-
    Gulftown6 coreConsumeri7 980X3.333.601333130Wx*x-
    Gulftown6 coreConsumeri7 9703.203.461333130Wx*x-
    Westmere4 coreDual XeonX56873.603.861333130W---
    Westmere4 coreDual XeonX56773.463.731333130Wx*x-
    Westmere4 coreDual XeonX56723.203.60133395Wx*x-
    Westmere4 coreDual XeonX56673.063.46133395Wx*x-
    Westmere4 coreDual XeonX56472.933.201066130Wx*x-
    Westmere4 coreDual XeonE56402.662.93106680Wx*x-
    Westmere4 coreDual XeonE56302.532.80106680Wx*x-
    Westmere4 coreDual XeonE56202.402.66106680Wx*x-
    Westmere2 coreDual XeonX56984.404.541333130W---
    Nehalem4 coreDual XeonW55903.333.601333130Wxxx
    Nehalem4 coreDual XeonW55803.203.461333130Wxx-
    Nehalem4 coreDual XeonX55702.933.33133395Wxxx
    Nehalem4 coreDual XeonX55602.803.20133395Wxx-
    Nehalem4 coreDual XeonX55502.663.06133395Wxxx
    Nehalem4 coreDual XeonE55402.532.80106680Wxx-
    Nehalem4 coreDual XeonE55302.402.66106680Wxx-
    Nehalem4 coreDual XeonE55202.262.53106680Wxxx
    Nehalem4 coreXeonW35803.333.601333130Wxx-
    Nehalem4 coreXeonW35703.203.461333130Wxx-
    Nehalem4 coreXeonW35653.203.461066130Wxx-
    Nehalem4 coreXeonW35402.933.201066130Wxx-
    Nehalem4 coreXeonW35302.803.061066130Wxx-
    Nehalem4 coreXeonW35202.662.931066130Wxx-
    Nehalem4 coreConsumeri7 9753.333.601066130Wxx-
    Nehalem4 coreConsumeri7 9653.203.461066130Wx**x**-
    Nehalem4 coreConsumeri7 9603.203.461066130Wxx-
    Nehalem4 coreConsumeri7 9503.063.331066130Wxx-
    Nehalem4 coreConsumeri7 9402.933.201066130Wx**x**-
    Nehalem4 coreConsumeri7 9302.803.061066130Wxx-
    Nehalem4 coreConsumeri7 9202.662.931066130Wx**x**-
    * Requires 4,1 to 5,1 firmware upgrade

    ** Some or all steppings of these CPUs don't work with certain newer Mac Pro firmware versions applied by High Sierra 10.13.5 updates and newer. See this thread. The thread also has a method for adding the code back to make the CPUs compatible again.


    Mac Pro 3,1
    Xserve 2,1

    • 64GB maximum RAM
    • The 3,1 MP is not compatible with all steppings. Processors with a 5-digit sSpec starting with "SLB" do not work. Those that start with "SLA" work. The sSpec is marked on the top of the processor. sSpec numbers listed in this table should work.
    • The 3,1 single-processor Mac Pro can be upgraded to dual-processor by adding a second CPU and appropriate heat sink. The CPUs must match including sSpec, so either get a second CPU that matches your existing CPU, or get two matching CPUs.
    Harpertown4 coreDual XeonX5482SLANZ3.2800150Wx-
    Harpertown4 coreDual XeonX5460SLANP3.16667120Wx-
    Harpertown4 coreDual XeonE5472SLANR3.080080Wxx
    Harpertown4 coreDual XeonX5472SLASA3.0800120Wx-
    Harpertown4 coreDual XeonX5450SLASB3.0667120Wx-
    Harpertown4 coreDual XeonE5450SLANQ3.066780Wx-
    Harpertown4 coreDual XeonE5440SLANS2.8366780Wx-
    Harpertown4 coreDual XeonE5462SLANT2.880080Wxx
    Wolfdale2 coreDual XeonX5272SLANH3.4080080Wx-
    Wolfdale2 coreDual XeonX5260SLANJ3.3366780Wx-

    Mac Pro 2,1 and 1,1
    Xserve 1,1

    • 32GB maximum RAM for 1,1 (increases to 64GB if flashed with 2,1 firmware)
    • 64GB maximum RAM for 2,1
    • For the 1,1 to use Clovertown CPUs properly, it needs a firmware flashed to 2,1.
    • The 1,1 to 2,1 firmware flash requires Snow Leopard (or newer) to run. It can be found here:,1094.0.html
    ArchitectureCoresGradeCPU-ModelsSpecSteppingGHzRAMWatt** (TDP)Watt** (idle)MP1,1MP2,1XS1,1
    Clovertown4 coreDual XeonX5365SLAC3B33.0667150W50Wx*x-
    Clovertown4 coreDual XeonX5365SLAEDG03.0667120W25Wx*xx
    Clovertown4 coreDual XeonX5355SLAC4B32.66667120W50Wx*x-
    Clovertown4 coreDual XeonX5355SL9YMB32.66667120W50Wx*x-
    Clovertown4 coreDual XeonX5355SLAEGG02.66667120W25Wx*x-
    Clovertown4 coreDual XeonE5345SL9YLB32.3366780Wn/ax*xx
    Clovertown4 coreDual XeonE5345SLAC5B32.3366780Wn/ax*xx
    Clovertown4 coreDual XeonE5345SLAEJG02.3366780Wn/ax*xx
    Clovertown4 coreDual XeonE5340SL9MYn/a2.453380W30Wx*xx
    Clovertown4 coreDual XeonE5340n/aG02.466780W25Wx*xx
    Clovertown4 coreDual XeonL5335SLAENG02.066750W24Wx*xx
    Clovertown4 coreDual XeonL5320SLA4QB31.8653350W24Wx*x-
    Clovertown4 coreDual XeonL5320SLAC9B31.8653350W24Wx*x-
    Clovertown4 coreDual XeonL5320SLAEPG01.8653350W24Wx*x-
    Clovertown4 coreDual XeonE5320SL9MVB31.8653380W30Wx*x-
    Clovertown4 coreDual XeonE5320SLACBB31.8653380W30Wx*x-
    Clovertown4 coreDual XeonE5320SLAEMG01.8653380W30Wx*x-
    Woodcrest2 coreDual Xeon5160SL9RTB23.066780Wn/axxx
    Woodcrest2 coreDual Xeon5160SLABSB23.066780Wn/axxx
    Woodcrest2 coreDual Xeon5160SLAG9G03.066765W8Wxxx
    Woodcrest2 coreDual Xeon5150SL9RUB22.6666765W24Wxxx
    Woodcrest2 coreDual Xeon5150SLABMB22.6666765W24Wxxx
    Woodcrest2 coreDual Xeon5150SLAGAG02.6666765W8Wxxx
    Woodcrest2 coreDual Xeon5130SL9RXB22.066765W27Wxxx
    Woodcrest2 coreDual Xeon5130SLABPB22.066765W27Wxxx
    Woodcrest2 coreDual Xeon5130SLAGCG02.066765W27Wxxx
    * 1,1 to 2,1 firmware upgrade recommended for stepping G0, _strongly_ recommended for earlier steppings.
    ** Values per CPU (-> x2 in a MP). Upgrade from DualCore to QuadCore CPU's usually requires fan control adjustments prior to stepping G0.

    Sources used (among others):, Wikipedia.


    • Thanks to Bokkow for helping with this. The information is formatted and presented nicely due to his work with BBCode tables, and he has contributed with a lot of the data as well.
    • Thanks to MacEFIROM and Netkas for creating and providing the firmware updates for Mac Pro. This has enabled countless people to upgrade to a newer generation of CPUs, which wouldn't be possible without the effort made by these two.
    • Thanks to everyone who ever upgraded a CPU and took the time to post about it here--there's a chance it was your post I saw that led to a CPU being verified above.
    • Thanks to those who took the time, money, and risk to shove more memory in their computer than others said was possible.
    • Thanks to everyone who helps to push the limits and usefulness of our computers.
    • Thanks to MacRumors and the mods for providing such a great forum for the above to happen in the first place. Especially the mod Arn, for enabling BBCode tables for this.
  2. flehman macrumors 6502


    Feb 21, 2015
    Thanks - this is a great resource. I wish there had been one wiki post with all this info in one place when I was doing my own research.

    One small point I would make is that there can be minor differences between an X-class CPU and its W-class equivalent that aren't covered here. For instance, the high temp tolerance of the X5690 is slightly higher than that of the W3690, which might be one reason to look at the X5690 a little more closely even for a single-CPU 4,1 or 5,1.
  3. nigelbb macrumors 65816

    Dec 22, 2012
    Great work! Might I suggest that you also include the TDP for each processor as you had on the table to posted on another thread? I am not sure whether it's ever a consideration when upgrading but it would be a nice to have for completeness.
  4. bokkow, Feb 5, 2016
    Last edited: Feb 6, 2016

    bokkow macrumors 6502


    May 3, 2012
    The Netherlands
    Thanks Nigelbb I will put this in the table as well, I agree with you that TDP can be a consideration when upgrading.
  5. ibarnett macrumors regular


    Aug 20, 2010
    Gold Coast, Australia
    --- Post Merged, Feb 6, 2016 ---
    Great work.
    You can add to Mac Pro 5,1 dual CPU:
    W5590 3.33GHz
    I have a pair working well here :)
  6. m4v3r1ck macrumors 68020


    Nov 2, 2011
    The Netherlands
    And yet another GREAT resource, thanks guys!!!

    --- Post Merged, Feb 6, 2016 ---
    Good additional info's!

  7. bokkow macrumors 6502


    May 3, 2012
    The Netherlands
    I have a whole Excel spreadsheet with separate tabs and even Xserve models included but there is no way to put a table on this forum for now. Still figuring out what would be best to do. I have W5590 on the list as well, thanks for the confirmation ;)
  8. bokkow, Feb 7, 2016
    Last edited: Feb 7, 2016

    bokkow macrumors 6502


    May 3, 2012
    The Netherlands
    @arn was kind enough to implement table possibility in BBCode for MacRumors right away :) So tables in the startpost will be up as soon as possible! (I'm hoping to finish up around the same time tomorrow)
  9. ActionableMango thread starter macrumors G3


    Sep 21, 2010
    Bokkow has been doing a lot of work on this, to get it better organized and more presentable. I've seen a draft table and it looks great. As soon as he's done I'll get the first post updated.
  10. pastrychef macrumors 601


    Sep 15, 2006
    New York City, NY
    I think at least one of the forum members have X5687 running in their 5,1. I'm curious if X5698 will work in the 4,1 and 5,1s.
  11. NOTNlCE macrumors 6502a


    Oct 11, 2013
    DMV Area
    I can safely submit that the 1,1 and 2,1 are compatible with Xeon L5335 Low Voltage Quad Cores @ 2.0GHz, I run them in my 1,1 and my Xserve.

    Also, the 1,1 -> 2,1 flash was NOT done on my machine, the processors are seen as Unknown, but work fine.
  12. bokkow macrumors 6502


    May 3, 2012
    The Netherlands
    Hey Pastrychef, would be great if it worked, fastest single core chips in the family, however, 4.1 and 5.1 firmware do not recognize X5687 or X5698, it has been confirmed quite a few times when you search the forum. If you find a user who has it up and running please let me know!

    Thanks! Will add this to the list! Great to know that some low voltage CPU's work; for the persons who want to make their MP low in energy consumption. If other people have low voltage models (which are not on the chart yet): please come forward :D
  13. ActionableMango thread starter macrumors G3


    Sep 21, 2010
    I really wanted the X5698 to work, because that chip would probably be ideal for me. When they finally became affordable enough on Ebay, I looked into it. Many people have said it wouldn't work, but I still held out hope because they hadn't actually tried so themselves.

    But eventually I found the following post. The MP won't boot with it installed:,852.msg11014.html#msg11014
  14. pastrychef macrumors 601


    Sep 15, 2006
    New York City, NY
    Oops. I just found the post and the guy was using X5677.
    --- Post Merged, Feb 8, 2016 ---
    Thanks for the info.
  15. ActionableMango thread starter macrumors G3


    Sep 21, 2010
    I've updated the first post with Bokkow's formatting. It is much improved! He also added Xserve compatibility and TDP wattage information.

    I've also removed the two processors that were likely compatible, but for which I could not find any verification (i7 980 and W3550). So the list is now entirely processors where I could find verification somewhere.
  16. m4v3r1ck macrumors 68020


    Nov 2, 2011
    The Netherlands
    Kudo's! Looking clean & mean...

  17. bokkow macrumors 6502


    May 3, 2012
    The Netherlands
    Happy to contribute! And again, special thanks to @arn for adding table functionality to MacRumors almost instantly after request.

    By the way, any suggestions/additions are welcome so that we can make the list as complete as possible! It's a list for and by the community :)
  18. Macsonic macrumors 65816


    Sep 6, 2009
    Great Work @ActionableMango and @bokkow on this resource. I've shared this thread to some of my clients who plan to upgrade their cMac Pros CPUs in their studios. Their cMac Pros are still running fine helping them bringing in incomes.
  19. scott.n macrumors 6502

    Dec 17, 2010
    Suggest adding some notes about the RAM types and requirements:

    DDR2 for 1,1 through 3,1 (with perhaps an additional note re: heatsinks)
    DDR3 for for 4,1 through 6,1
    Can't mix Registered and Unregistered
    ECC vs non-ECC


    Also, the XServe3,1 uses lidless processors, like the dual MacPro4,1.
  20. ActionableMango thread starter macrumors G3


    Sep 21, 2010
    This is a good idea. Also:
    When 3 (or 6) sticks is better
    When 4 (or 8) sticks is better
    Heatsink requirements in a 1,1/2,1
    How to tell if you need more RAM or if it won't help at all
    Valid configurations (pairs are required in 1,1 and 2,1 for example)

    It's added to the to-do list, but I'm a bit busy right now with just the CPU updates. ;)

    Just the dual-CPU versions, or also the single-CPU version?
  21. p.l macrumors member


    Jun 3, 2015
    I can confirm a E5 2696 v2 @ 2.5ghz working in a nMP
  22. bokkow macrumors 6502


    May 3, 2012
    The Netherlands
    Quite a lot of info for side notes, maybe additional (small) tables would provide overview. Going to experiment a bit with that idea perhaps tomorrow, I am a bit busy at work in the coming days.

    How to tell if you need more ram can be captured in a general side-note, applicable for any machine running OSX :)

    Both, just checked. Not sure if you can do with adding washers and 'normal' CPU's
  23. ActionableMango, Feb 8, 2016
    Last edited: Feb 9, 2016

    ActionableMango thread starter macrumors G3


    Sep 21, 2010
    I updated the list with recent comments, to sort the fastest processors at the top, and to add additional, verified processors:
    • E5 2696 v2
    • E5320
    • L5320
    • E5340 (Weird processor... I couldn't find it in Intel ARK, but there are plenty of other resources that mention it)
    If you posted here or PM'd me with a verified processor not on the list, thank you for verifying and letting me know.

    It may be enough information to warrant its own separate thread.
  24. NOTNlCE macrumors 6502a


    Oct 11, 2013
    DMV Area
    A note on those L5335s - they run fine WITHOUT a flash in the 1,1 not necessarily required. Also, they run great in my Xserve 1,1 - simply seen as Unknown, but spot on performance.
  25. ActionableMango thread starter macrumors G3


    Sep 21, 2010
    Okay, I've changed "required" to "recommended" and added the Xserve.

    I do have a concern about it when I was researching 1,1 CPU upgrades to Clovertown processors. Some people reported they worked fine (other than the "unknown" label). Others reported they worked fine most of the time, but unfortunately had occasional kernel panics--and then when the firmware update came out and they updated, the kernel panics went away. There were multiple reports of these KPs that went away with the firmware update, so I hesitate to indicate that they work 100% without it.
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