Strange GPU behavior on Mac Pro 3,1

Discussion in 'Mac Pro' started by Shadow9x99, May 30, 2018.

  1. Shadow9x99 macrumors newbie

    Shadow9x99

    Joined:
    Apr 23, 2018
    Location:
    Brockville, OH
    #1
    I have two GPUs for my early 2008 mac pro (2x 3.2ghz Xeon, 16GB OWC Ram), the first is an EVGA GTX 285 flashed with the mac efi and the second is an Apple radeon 5770. The system runs OS X 10.11.6 just fine.
    The strange thing is that in most games on OS X the 5770 outperforms the 285 by a signifigant amount.

    For example: Life Is Strange at high settings can barely stay above 20FPS (avg 23) with the 285 but never drops below 30 (avg 45) with the 5770.
    FireWatch at low settings runs at about 30FPS Avg on the 5770 but the GTX285 runs at about 10FPS for a few seconds and then OS X crashes.
    Tomb Raider 2013 Runs perfectly fine on both cards with the GTX 285 outperforming the 5770 by a healthy margin IF you check the box that says "Use Legacy OpenGL" (this box doesn't have to be checked for it to work with the 5770). This led me to believe it was an API issue, so I fired up OpenGL Extensions Viewer only to discover that they both only support OpenGL 2.1 and the only differences I could find were the max texture size (5770=16384 vs 285), max uniform vertex components (5770=3072 vs 285=4096), max uniform fragment components (5770=3072 vs 285=2048), max geometry uniform components (5770=3072 vs 285=2048), and max varying floats (5770=128 vs 285=60). I tried running the built in Iron Fist Boxing Kings test using OpenGL 2.1 on both cards and the GTX285 managed 23FPS while the 5770 was at 154FPS!
    Any application that uses the GPU for computing (i.e. FCPX) seems to run a fair bit slower with the GTX285, but I haven't actually measured this.

    So maybe its the drivers? I tried installing the latest web drivers for the GTX285 and it made no difference with anything. It isn't the hardware itself because using bootcamp with Windows 10 the GTX 285 smokes the 5770 in every test I've ran.

    My google-fu has been no help, so if anyone knows why it's like this or how to fix it I'd sure love to know.

    Thank you in advance
     
  2. bsbeamer macrumors 68000

    Joined:
    Sep 19, 2012
    #2
    In the latest OS on 4,1 & 5,1 there are some issues with dual GPUs, especially from dual manufacturers. Unsure if 3,1 is impacted by this and haven't been actively using 10.11.X for awhile.

    Does removing one of the two GPUs (only using one at a time) make any difference?
    Are you using CUDA for anything?

    FCPX generally prefers AMD GPU vs. NVIDIA GPU on the latest systems. With running 10.11.X you are likely more impacted with OS performance issues and latest software than any specific driver related issues. The latest OS offers several benefits for Apple software in terms of processing performance (especially with FCPX).

    Might be worth looking into some of the workarounds to get 10.13 installed if FCPX is important.
     
  3. Shadow9x99 thread starter macrumors newbie

    Shadow9x99

    Joined:
    Apr 23, 2018
    Location:
    Brockville, OH
    #3
    Nope, just tried pulling out the 5770 and it made no difference to anything. Something else I just noticed though is that fps is the exact same wether the game is maxed out or at its lowest settings.

    I don't use CUDA for anything, and I've tried running 10.13.3 back when I only had the 5770 and there were some ui bugs as well as GPU related stability problems in FCPX. I've wanted to move back to 10.13 with the just GTX285 (as I hear an nvidia card doesn't have those issues) but I don't want to loose so much of my gaming performance in the process...
     
  4. Shadow9x99 thread starter macrumors newbie

    Shadow9x99

    Joined:
    Apr 23, 2018
    Location:
    Brockville, OH
    #4
    I just upgraded to MacOS 10.13.4 using DosDude1's patch tool and it did improve the GTX285's performance in some games by 2-3FPS, but FireWatch still crashes and it's still way behind the 5770
     
  5. crjackson2134 macrumors 68040

    crjackson2134

    Joined:
    Mar 6, 2013
    Location:
    Charlotte, NC
    #5
    Is the 5770 an Apple/AMD EFI Card, or a Flashed PC model?

    Try pulling the GTX Card and then check the Windows performance. Also make sure it’s not connecting at 1/2 the normal GT/s.

    Just something to investigate...
     
  6. orph macrumors 68000

    orph

    Joined:
    Dec 12, 2005
    Location:
    UK
    #6
    i know some of the ATI cards age better than the nvidia cards, maybe it has something to do with that also in osx land ATI cards will have better drivers.
    found a comparison
    https://www.anandtech.com/bench/product/538?vs=520
    the two cards look fairly close at times, so better drivers in osx land sound like a good bet.

    also if you want a nvidia card something like a GTX660 will be miles faster than both cards in most tasks.
    gtx 660 v gtx 285 https://www.anandtech.com/bench/product/520?vs=660
    gtx 680 v gtx 285 https://www.anandtech.com/bench/product/520?vs=555
     
  7. bsbeamer macrumors 68000

    Joined:
    Sep 19, 2012
    #7
    According to this compatibility list for FCPX, the GTX 285 is not a supported GPU in Sierra/High Sierra:
    https://support.apple.com/en-us/HT202239

    The GTX 285 is not a specific incompatible card across the board, but it is not listed as compatible with Sierra/High Sierra. The GTX 285 under OpenCL in Yosemite is the max OS supported. You would actually have to downgrade to OSX 10.10.5 to meet the compatibility requirements with that GPU.

    The Radeon HD 5770 is listed as compatible with latest updates.
     

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