Poor GPU performance with 3,1

Discussion in 'Mac Pro' started by tpivette89, Sep 29, 2018.

  1. tpivette89 macrumors 6502

    tpivette89

    Joined:
    Jan 1, 2018
    Location:
    Newark, DE
    #1
    I have a cMP 3,1 with a HD Radeon 7970 GPU. CPUs are a pair of X5272s (2-core at 3.4ghz), RAM is 16GB at 800mhz (8 x 2GB). Running 10.11.6 on a SSD using one of the SATA II drive bays. For monitors, I'm running a pair of ACD 23" aluminum versions.

    Running Unigine Valley on high settings (not Ultra), I'm only averaging around 27fps. With the same card on my 4,1 (flashed to 5,1) I get an average framerate of 50fps... however, that is a 12 core machine with more RAM (24GB).

    What is keeping the GPU from reaching the performance figures I know its capable of? Is there something I'm missing or lacking?
     
  2. Ludacrisvp macrumors 6502

    Joined:
    May 14, 2008
    #2
    I find it interesting you are running dual dual core processors in the 3,1 ... curious why you have that config. Was it just to get 3.4 GHz vs 3.2?

    Anyways for the GPU it is probably because the 3,1 isn’t running the GPU with PCIe 2.0 x16 and is probably doing 1.1 or 1.0.
     
  3. tpivette89 thread starter macrumors 6502

    tpivette89

    Joined:
    Jan 1, 2018
    Location:
    Newark, DE
    #3
    I just wanted to see if these CPUs worked in the 3,1 Mac Pro (originally when I got the machine, they were not included on the compatible list). Plus, yes, I wanted the better single core scores... but now realize that the difference between the 3.4 vs the 3.2 in single score is basically negligible.

    Why would it not run PCIe 2.0? Is this something that has only happened recently due to the new 138 firmware? Or is it a limitation of the 3,1?
     
  4. orph macrumors 68000

    orph

    Joined:
    Dec 12, 2005
    Location:
    UK
    #4
    it's cpu speed & drivers, netkas did a bunch of posts on it
    http://netkas.org/?cat=12
    that was from a quick look, he looked in to it a lot.

    has nothing to do with PCI speed
     
  5. Fl0r!an macrumors 6502a

    Joined:
    Aug 14, 2007
    #5
    Ther's a known power management bug when running GCN GPUs in a 3,1. A workaround is trashing AppleIntelCPUPowerManagement kexts. There's more information on this topic here and on netkas.org.

    Additionally, the GPU will be CPU-bound due to quite slow single core performance of those CPUs.
     
  6. tigerintank macrumors regular

    Joined:
    Jun 16, 2013
    #6
    Is there a new firmware for the MP 3,1? Can someone point me to some info pls
     
  7. tsialex macrumors 601

    tsialex

    Joined:
    Jun 13, 2016
    Location:
    Brazil
    #7
    No, only for MP5,1 and MP6,1. MP3,1 is unsupported since El Capitan.
     
  8. tigerintank macrumors regular

    Joined:
    Jun 16, 2013
    #8
    ok thank you
     

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7 September 29, 2018