CPUs compatible with Mac Pro 3.1

Discussion in 'Mac Pro' started by PineShack, Sep 4, 2015.

  1. PineShack macrumors newbie

    Joined:
    Jan 17, 2015
    #1
    Does anybody know if it's possible to use a model of CPU in a 2008 Mac Pro that Apple never used from the factory? I have a pair of E5450 Xeons I'd like to use, as they're very nice, low heat CPUs. I put them in, but the machine wouldn't post. Could this be because the processors aren't recognized by the firmware?
     
  2. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #2
    It is possible to use certain CPUs in a Mac Pro that Apple never provided as stock, but not all CPUs will work.

    An E5450 should work if its SLANQ (C0 stepping). An E5450 SLBBM (E0 stepping) will not work.
     
  3. PineShack thread starter macrumors newbie

    Joined:
    Jan 17, 2015
    #3

    Ah, that explains things. The pair I have here are the SLBBM stepping. For future reference, do you know of a list anywhere of which processors will and won't work in each of the Mac Pros?
     
  4. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #4
    Sorry I don't know of a list specific to the Mac Pro. I think you can insert any C0 stepping Harpertown, but I'm not sure.

    Here is a list of Harpertowns:
    https://en.wikipedia.org/wiki/List_of_Intel_Xeon_microprocessors#.22Harpertown.22_.2845_nm.29

    I'm not sure about the low voltage ones, so I'd avoid the L54xx series unless you see someone has already tried them. Stick with the E54xx and X54xx with C0 stepping and I think you'll be fine. No promises though--I'm just a random dude on an Internet forum!

    If you want a for-sure verified to work in Mac Pro CPU model, check out some of the other 2008 Mac Pro CPU threads here to see what people have successfully installed. That's what I did for my 2010.
     
  5. MacVidCards Suspended

    Joined:
    Nov 17, 2008
    Location:
    Hollywood, CA
    #5
    Sitting at a restaurant so off the top of my head, 5482 is fastest, 5492 a no no
     
  6. Kaspin macrumors member

    Kaspin

    Joined:
    Jan 15, 2015
    #6
    The officially supported CPUs:
    E5462 SLANT 2.8Ghz 80W
    X5472 SLASA 3.0Ghz 120W
    X5482 SLANZ 3.2Ghz 150W

    These are all C0 Stepping and 1600FSB. The only other harpertown that is c0 Stepping and 1600FSB is the E5472 SLANR 3.0Ghz 80W, and I don't know of anyone reporting that it is usable, nor do I know if any of the 1333FSB ones would work.

    The X5492 3.4Ghz would have been ideal, but it's not available in a C0 stepping.
     
  7. PineShack thread starter macrumors newbie

    Joined:
    Jan 17, 2015
    #7
    Thanks for the help. I think this is starting to make sense to me. From what you've all said here, as well as what I read in this thread, it seems the C0 steppings in this processor family are compatible, for the most part, and the E0 are very likely not. I guess I'll keep an eye out for a cheap pair of SLANQ e5450 Xeons. It's not a huge priority, though, there's not a huge benefit to be gained. A bit faster with combined with lower heat would be nice, but the e5462s that are in there now are not so bad.

    Thanks again for the responses.
     
  8. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #8
    Well, if Kaspin is right, you can't use the 1333 CPUs either, even if they are Harpertown C0 stepping. It looks like your options are limited to the three he suggested unless you've found someone that has verified the E5450 works in a 3,1 MP.
     
  9. PineShack thread starter macrumors newbie

    Joined:
    Jan 17, 2015
    #9
    Well then, maybe I'll just put it out of my mind and move on. A bit less heat would have been nice, because fan noise really irritates me, but the current CPUs rarely provoke the fans to go up much faster than baseline anyway. A lower baseline fan speed for cooler temperatures would be nice, but I gather there is no way to achieve that. On the whole, it looks like it would probably be best to just leave it be.

    Thanks for your help.
     
  10. PineShack thread starter macrumors newbie

    Joined:
    Jan 17, 2015
    #10
    I notice that there are quite a few results at Geekbench for Mac Pro 3.1s running E5450 Xeons. I don't know enough about Geekbench and its various versions to know if this means anything, though. Is it possible to input values for the type of computer and motherboard, or is it entirely automated by the software? I would think that allowing testers to change those values to whatever they like would devalue a comparative database, but I've been around long enough to know that what I think seldom has any bearing on reality. This would seem to suggest, however, that there are 3.1s out there running e5450s.
     
  11. Umbongo macrumors 601

    Umbongo

    Joined:
    Sep 14, 2006
    Location:
    England
    #11
    Mac Pros shipped with both E5472 and X5472s right from January 2008. Apple bought up the whole of the early supply of 1600MHz CPUs and used them all. :)
     
  12. PineShack thread starter macrumors newbie

    Joined:
    Jan 17, 2015
    #12
    One last appeal I guess ...:) Is there anyone out there who has successfully run E5450 Xeons in a Mac Pro 3.1?
     
  13. Fangio macrumors 6502

    Joined:
    Jan 25, 2011
    #13
    I think looking at the Geekbench browser is the best approach. Obviously you need to filter it with MacPro3,1 and E5450

    https://browser.primatelabs.com/geekbench3/search?q=MacPro3,1+E5450

    but probably there are many hackintoshs included also. So maybe you'd just have to add something like processor ID or motherboard to this search to find only genuine 3,1 cMPs... however my knowledge about 3,1 machines is limited so someone else would have to chime in and tell you what could make the results distinctive.
     
  14. PineShack thread starter macrumors newbie

    Joined:
    Jan 17, 2015
    #14
    Thanks for the response Fangio. The existence of those records at Geekbench is part of what got me thinking that the E5450 might work in a Mac Pro 3.1. Unfortunately, after further reading, it now seems very likely to me that those results were probably from Hackintoshes with spoofed smbios. I found several discussions at various fora which suggested that any Geekbench result showing a Mac Pro 3.1 is probably a Hackintosh, and that genuine Macs would be listed as Mac Pro (Early 2008). A search with those terms shows only factory CPUs. I am increasingly coming to believe that the 3.1 won't run anything but the CPUs Apple shipped them with.
     
  15. PineShack thread starter macrumors newbie

    Joined:
    Jan 17, 2015
    #15
    I've now done a fair amount of research on this topic and have come to firmly believe that no CPUs other than the original C0 stepping 54xx series Xeons will work in the early 2008 Mac Pro, which, of course, is what you guys were telling me all along. Sometimes I'm a bit reluctant to accept reality. :p

    All those Geekbench scores with different CPUs in a 3.1 are very misleading. They're all Hackintoshes, I'm sure. I have also seen sellers on eBay selling other Xeons, like the E5450, as upgrades for 3.1 Mac Pros, and I took that as evidence that they must work. In reality, though, I think it was only evidence that some people will say anything to make a sale.

    Anyway, no big deal. The compatible CPUs are a decent match for the rest of the hardware in a 3.1. Time to learn to be happy with what I've got. :)
     
  16. Bubalight macrumors newbie

    Joined:
    Apr 22, 2015
    #16
    I was curious enough about this that since I had a base model 3,1 (2.8 8 core e5462) and some e5450s laying about I tried with a pair of the SLANQ e5450 in a 3,1 and it DOES WORK.
    The SLANQ is a 1333mhz bus. I was already using non apple 5300 FB-DIMM ram, if you choose to upgrade, you would not be able to use your stock ram at the full 6400 speed. It might not even work at all. But since 5300 is much cheaper, this is not a major issue.
    This upgrade is only theoretically at best a 7% upgrade, for most uses I think that using slower ram is not really even a measurable performance hit. By the numbers your memory bandwidth is 17% less. But if you already use the cheaper slower ram this is will not affect you. But it isn't an easy install ether, and I wouldn't recommend it. One positive, at least according to the Intel specs the TPD is the same.
    I did not try with a SLBBM (e0) e5450, but I would not expect that chip to work.
     
  17. PineShack thread starter macrumors newbie

    Joined:
    Jan 17, 2015
    #17
    Just when I thought I had found peace on this issue . . . :)

    Thanks for your efforts Bubalight. I'm interested again, although I'm not entirely sure why, given the probably small gains to be had with this change. I already have a bunch of PC-2-5300 memory in this machine that I moved over from my MP 1.1, so that's not an issue. I'm thinking that the small differences in clock speed for the memory and CPU would likely cancel each other out to the point where the performance is nearly identical. Geekbench scores seem to support this assumption. So the main advantage to be gained would be with regard to power consumption, heat and associated fan noise. There is a fair bit of anecdotal support out there for the E5450 being a good, stable, cool-running chip, but in real terms I'm not sure if there would be enough of a difference from my current e5462s to make this in any way worth doing. Still, it's nice to know it's possible, provided it's the C0 SLANQ chip. The ones I unsuccessfully tried were SLBBM.

    For now, I think I'll let the idea drop. Maybe someday I'll give it a go if I find a pair of SLANQ chips for cheap, or if my judgment fails me some night when I'm browsing eBay while drinking. :)
     
  18. Bubalight macrumors newbie

    Joined:
    Apr 22, 2015
    #18
    I don't have the chips to try it, but since the SLANQ works, the 3.16ghz SLANP x5460 would be a good candidate to try for a bigger performance boost.

    Also if you are really feeling adventurous, another possibility which would be more of a side-grade then an upgrade, but with better single thread performance for the trade-off of loosing half the cores, the SLANJ x5260 3.33ghz dual core with 1333 bus, or also the SLANH x5272 3.40ghz dual core with 1600 bus are all the right stepping and might be supported in a 3,1
     
  19. PineShack thread starter macrumors newbie

    Joined:
    Jan 17, 2015
    #19
    To be honest, I can't remember now why I thought the E5450 was going to be such a great improvement. I had it in my head that it was going to be a cooler chip than a E5472 at the same speed, but now I can't find any support for that assumption. In the interest of science, though, and because I've made a bit of a fuss over it in this thread, I'm going to watch the bay for a couple of SLANQ E5450s. I'm also now a bit interested in the low voltage L5420, for which the C0 stepping is SLARP.
     
  20. jdryyz, Feb 27, 2016
    Last edited: Feb 29, 2016

    jdryyz macrumors regular

    jdryyz

    Joined:
    Jun 12, 2007
    #20
    Recently, I've been looking into picking up a real Mac Pro 2008 as they've become more affordable. I've seen them go for lower than $400. I have a complete "Hackintosh" system based on hardware that closely resembles the 2008 Mac Pro (HP xw8600). Interestingly enough, I have two E0 stepping E5450s installed that work fine. Funny that the real Mac Pro won't post with these as the OS seems to have no trouble (tested Mountain Lion and Mavericks).

    I am getting a bit tired with the delicacy of the Hackintosh environment, however. One wrong system update/change and BAM! More restore work necessary. Plus, I would like to use the latest OS available which is not always easy to get working on a Hackintosh.

    Not being able to move all my upgrade parts from the current machine to a real Mac Pro is kind of a bummer. I know others suggest not even working with Pros older than 2009. I would not mind if I can find one cheap. There seems to be a sizable jump in cost between the two years.
     
  21. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #21
    This thread is out of date. There is now a CPU compatibility list here:
    http://forums.macrumors.com/threads/mac-pro-cpu-compatibility-list.1954766/

    E5450 is not on there, but several other options are.

    There is a sizable jump between 2008 and 2009 because the 2009 is substantially better in several ways, especially if you do the firmware update.
     
  22. jdryyz macrumors regular

    jdryyz

    Joined:
    Jun 12, 2007
    #22
    Got my sights on a 2009 model now. I think I'm in for a wait though.
     

Share This Page