MP 1,1-5,1 Dual AMD & performance

Discussion in 'Mac Pro' started by JM-Prod, Jun 13, 2019.

  1. JM-Prod macrumors regular

    Joined:
    Apr 10, 2011
    #1
    I'm still using MacPro's 5.1 - and I've made an extra cable for power distribution from the SATA ports to the GPU-area for added power capabilities running the later GPU's from Nvidia. However, due to Mojave's lack of Nvidia drivers, I've acquired a pair of cheap second hand Radeon 580RX to test double 8-pin power consumption and Mojave on 5.1 workstations.


    They seem to process 6k Raw-files at almost real-time speed, but they don't seem to be able to both process and read at the same time in RedCine it seems. It buffers a segment in what seems like realtime, and then plays it back, etc., etc. It also stutters in DaVinci Resolve.

    Should they be linked with any kind of cable to work better in tandem on a Mac?
     
  2. startergo macrumors 6502a

    startergo

    Joined:
    Sep 20, 2018
  3. krakman macrumors regular

    Joined:
    Dec 3, 2009
    #3
    you might be hitting a cpu bottleneck, after all it is almost a 9 /10 year old cpu design.

    I use a RX Vega 56 GPU and edit in FCPX but all my footage is from dslr and not in Raw format.

    there is a hack to enable hardware h264 encoding/decoding just search this forum, it might help you???
     
  4. h9826790 macrumors G5

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #4
    AFAIK, Crossfire is only for 3D Alternate Frame Rendering in Windows gaming. Not quite related to video editing.

    MacOS, and some video editing software clearly can utilise multi GPU for computing / rendering.

    e.g. Luxmark clearly shows that it can utilise the 2nd GPU quite well.
    V3 970 280.jpg
    V3 10.11.4 b4 970.jpg

    In FCPX, both GPU can also be used simultaneously.
    FCPX Rendering.jpg

    BruceX also shows almost 100% improvement when 2nd 7950 is installed.

    What I've heard is that dual RX580 isn't working quite well in macOS. Some users reported that the 2nd GPU basically sits idle and doing nothing all the time. No idea what the problem is, but definitely nothing about "no Crossfire support in macOS".

    Since the 7,1 will allow user install multiple Polaris GPU (and Apple will sell Polaris GPU as well), I believe they will fix this issue later. But at this moment, seems better to go for a single powerful GPU (e.g. Radeon VII), especially for those running 10.1.4.5.
     
  5. SoyCapitanSoyCapitan

    Joined:
    Jul 4, 2015
    Location:
    Paris
    #5
    Barefeats has results of dual Radeons. They perform quite strongly on macOS but depends on the app.

    Latest Resolve 16 beta playback is pretty bad on even a single GPU. Previous beta was fine. But thing to note is Resolve renders most codecs on CPUs. Only uses GPU for real time grading and some FX.
     
  6. startergo macrumors 6502a

    startergo

    Joined:
    Sep 20, 2018
    #6
    Out of curiosity Nvidia (Kepler) and AMD do not join forces in any application in Mojave?
     
  7. orph, Jun 13, 2019
    Last edited: Jun 13, 2019

    orph macrumors 68000

    orph

    Joined:
    Dec 12, 2005
    Location:
    UK
    #7
    are you using two AMD RX 580 if so how do you suply power to them?
    one 6pin + sata for each card, is that ok? (i relay dont know never tryed)

    i asume the app's you want to use is RedCine & Resolve.
    i dont know redcine but a quick google found this
    https://ymcinema.com/2019/02/07/red...leased-nvidia-dedicated-but-for-windows-only/
    'It’s important to note that according to the update that Dual GPUs currently do not provide performance improvements.'

    and for Resolve you are using the paid version? not the free one as dual GPU use is only in the paid one.
    if you are on the paid version of Resolve did you corectly set all the prefrencesto use the dual GPU?

    also play with openCL v metale in resolve, for me openCL was faster but that may be difrent for you.

    and you mention 6k Raw-files, thats big files so do you have lots of ram & fast drives? + realistic expectations
    full rez playback may just be to much
    what CPU do you have, not the 2.4ghz one?

    worth using activity monitor to watch gpu use when you use the apps to check if there being used and how much.
     
  8. SoyCapitanSoyCapitan

    Joined:
    Jul 4, 2015
    Location:
    Paris
    #8
    The free version of Resolve for macOS supports two GPUs (including dGPU+eGPU combo), the Windows free version is single GPU.
     
  9. orph macrumors 68000

    orph

    Joined:
    Dec 12, 2005
    Location:
    UK
    #9
  10. SoyCapitanSoyCapitan

    Joined:
    Jul 4, 2015
    Location:
    Paris
    #10
    Don’t know why they say that. Load the free version on trash can or Mac with external graphics. I see with my own eyes daily the app auto selects both cards. I have to manually make it only select the external one.
     

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9 June 13, 2019