Why FCPX is not faster with RX580 8gb

Discussion in 'Mac Pro' started by carambo, Oct 6, 2018.

  1. carambo macrumors member

    Joined:
    Aug 29, 2009
    #1
    Hi, I have upgraded my MP with a new RX580 8gb Pulse, to replace my old 5870, and I am very surprised that actually I don't see any benefit in FCPX. I thought a 8gb RAM in the video card would allow to process more frames and speed up the editing process, particularly when adding effects, compare to the 1gb in the 5870, but no :)
    I am on High Sierra with 32go RAM.
    Anyone has explanations about this ? And any recommendations how to leverage this new card, like using another editor (Premiere,...) ? Txs
     
  2. Socket macrumors regular

    Socket

    Joined:
    Jul 9, 2015
    #2
    have you tried a BruceX Test?
    you have both card installed at the same time? If yes, you must swap out the old one, because FCPX "work" with the lower one (don't know why)...if you have installed only the 580, then it works better
     
  3. carambo thread starter macrumors member

    Joined:
    Aug 29, 2009
    #3
    No I have only the RX580 installed, but FCPX is not better, or may be marginally, but I was expecting much more improvements
     
  4. namethisfile macrumors 65816

    namethisfile

    Joined:
    Jan 17, 2008
    #4
    I have a similar sentiment. I recently acquired a Pulse RX 580, as well. I came from RX 460 and I didn't see my experience in FCPX snappier, faster or smoother between RX 460 and RX 580. Even, though, when running Geekbench 4 OpenCL and Unigine benchmarks shows the RX 580 trouncing the RX 460... under FCPX, there doesn't seem to be any observable difference.

    This is when applying transitions, scrubbing on the timeline, etc. Also, export time doesn't improve, as well, using H264.

    So, I feel like I wasted $240+tax+shipping on the RX580.... Is there a "Doh!" emoticon? If so, ***Doh-moticon***
     
  5. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #5
    RX580 is mainly to improve rendering.

    For time line, as long as using ProRes, that should be storage speed limiting. And if not using ProRes, and directly editing H264 / H265, then Apple doesn't let the RX580 do hardware decoding in FCPX yet. That's why it can't be smooth.

    For export, encoding is purely CPU job, upgrade GPU won't help anything. Again, Apple not allow us to use the RX580's hardware encoding in macOS yet.
     
  6. carambo thread starter macrumors member

    Joined:
    Aug 29, 2009
    #6
    Txs for the info. To your knowledge, is it the same with Premiere or another editor, or is it related to the OS and Mac hardware, whatever is the software ?
     
  7. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #7
    OS limiting. The same card on cMP in Windows can do H264 and H265 hardware decoding / encoding flawlessly.
     
  8. slamjack macrumors member

    slamjack

    Joined:
    Jul 22, 2011
    Location:
    Moscow
    #8
    Same here. In general, i edit jpeg or PNG image sequences in FCPX (cartoon animatics) — timeline is not smooth, it is laggy, dragging and dropping is laggy, although rendering codec of the project is 422 LT, and all the images are compressed and held on PCI-e SSD.

    RX580 definitely has bottle neck, caused by OS now, and Mojave did not change anything.
    What modern cards (nvidia, vega 56?) don't have these limitations?
     
  9. thomasthegps, Dec 6, 2018 at 7:18 AM
    Last edited: Dec 6, 2018 at 7:28 AM

    thomasthegps macrumors regular

    Joined:
    Sep 23, 2015
    Location:
    France
    #9
    Apple doesn’t want an old mac to compete with their newer machines so they have purposefully disabled hevc encode/decode on the gpu. Fcx and other apps cant utilize the gpu features if they aren’t exposed by the os...

    Don’t expect any other card to offer better performance because apple has made it difficult for nvidia to use the gpu decode api, and all other amd cards use the apple driver that purposefully disables gpu features... (This has been proven with the 10.14.1 update. The RX 580 had hevc decoding abilities in 10.14.0 but apple decided to disable it in 10.14.1.)

    This is by definition programmed obsolescence.
     
  10. smirk macrumors 6502a

    smirk

    Joined:
    Jul 18, 2002
    Location:
    Orange County, CA
    #10
    Programmed obsolescence would be if older computers blocked hardware decoding, while newer ones enabled it. You would naturally be prompted to buy a new machine to get the added performance.
     
  11. thomasthegps macrumors regular

    Joined:
    Sep 23, 2015
    Location:
    France
    #11
    Which is what apple is doing... the hevc support in 10.14.0 probably cam from the imac pro. As soon as apple realized that decode functionality worked for the rx 580 they disabled it...
     
  12. kohlson macrumors 68000

    Joined:
    Apr 23, 2010
    #12
  13. h9826790 macrumors G4

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #13
    BruceX itself has nothing wrong. However, you can't use it as indicator for H264 export benchmark. The test was decided to measure rendering speed, and only export in ProRes.

    If you want to measure rendering + export H264, you can always mod the process, so that FCPX will export the BruceX project in H264, and you can time it accordingly.

    If you said BruceX is not accurate because it can't reflect the H264 export time.

    It's like running an OpenCL test and complain it's not a good indicator for DirectX performance.
     

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