MBP Retina 15" Mid 2015: Bottleneck Multi CAM 4K Edit

Discussion in 'MacBook Pro' started by Halbertus, Oct 20, 2016.

  1. Halbertus macrumors newbie

    Halbertus

    Joined:
    May 6, 2015
    #1
    I am giving feedback to students and future teachers at university on how to perform in speeches and presentations. My Job at universitity requires that I often edit Multicam videos in Adobe Premiere Pro.

    Recently we upgraded our video equipment to integrate 4K recording. So that puts a lot more load on my MacBook when cutting files and switching streams in Premiere.

    [​IMG]

    There seems to be a problem with throttling, as Playback in Realtime will work fluid for a minute or two. Then the fans inside my MacBook start to spin quite loudly and I get lots of dropped frames.

    I am asking myself whether I am reaching the limits of my CPU or my GPU processing power. Is there any way to find out, which factors in most for the stuttering playback?

    iStat Menu is showing a constant CPU Usage of about 70-85%, whether stuttering occurs or not. (So there should still be little room left in theory)
    For the discrete graphics card unfortunately there is no information given on how its being stressed.

    In case they origin from my graphics performance, my idea to circumvent these issues would be to use an external GPU (i.e. Bizon Box + GTX970) to put off some load.

    If the limitation is from the Intel CPU I probably need to consider switching to a more powerful desktop computer. (Mac Pro of 2013?)

    Any suggestions on how to find out?

    [​IMG]
     
  2. maratus macrumors 6502a

    maratus

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    #2
    Temps on the screenshot are perfectly fine for heavy load and your CPU shouldn't have any thermal throttling at that moment. To make sure use Intel Power Gadget to see its operating frequency over time

    As far as OpenCL goes, the dropped frames should be related to GPU operation. It may throttle itself down, although not because of heat but strict power consumption limits.
     
  3. priitv8 macrumors 68020

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    #3
    Can you switch to using optimized or proxy media during your editing workflow to reduce the burden on the CPU and GPU while performing the edits???
     
  4. jerryk macrumors 68030

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    SF Bay Area
    #4
    You might want to check the Adobe Premier Pro forums. There are several threads with issues with the AMD M370X.
     
  5. Halbertus thread starter macrumors newbie

    Halbertus

    Joined:
    May 6, 2015
    #5
    Thanks a lot for your replies!

    I have been further investigating the issue in the last few weeks. Especially the Intel Power Gadget has proven to be a handy tool as it is quite easy to determine whether the CPU is throttling. iStat Menu won't show the actual frequency of the CPU, Intel Power Gadget does.

    During my test I came up with some more general impressions that might be related to the industrial design of the MacBook Pros Unibody enclosure and how it handles heat.

    I am not quite sure how to proceed, just wanted to update this post as a reference.

    1. Only MacBooks internal screen used, no external display => results in no dropped frames, fans spinning loudly, CPU frequency at about 2,5 Ghz constantly
    2. Only external HiDPI screen used (Dell UP2715K), MacBook in clamshell mode => lots of dropped frames after as little as 2 minutes of playback. Intel Power Gadget shows CPU frequency dropping to 1.8 GHz
    3. External HiDPI screen and internal screen used, MacBook opened (for better airflow) => lots of dropped frames after several minutes of playback. Intel Power Gadget shows CPU frequency dropping to 1.8 GHz
    4. Only external HiDPI screen used, MacBook opened - internal display switched off => lots of dropped frames after several minutes of playback. Intel Power Gadget shows CPU frequency dropping to 1.8 GHz
    5. Only external screen used, scaled resolution of 2560x1440 (Lower DPI), MacBook opened - internal display switched off => results in no dropped frames, fans spinning loudly, CPU frequency at about 2,5 Ghz constantly
    Definately the MacBook Pro is reaching its limits in this scenario. Clearly I can see, that there is CPU throttling taking place. Although it seems strange to me, that I can get constant realtime video playback, when lowering load of the discrete graphics card i.e. by reducing the desktop resolution / the amount of pixels it has to push.

    In comparison to a midrange Windows desktop (Intel Quadcore, mediocre nVidia GPU, worth 1100€ in total), that i had the opportunity to play with recently, the MacBook definately falls short.

    I would be interested to test, whether an external GPU (Akitio Thunder 2 + GTX 970) would expand performance. Unfortunately it's kind of a big investment while there is mixed information on how effective this upgrade might be.
    From my understanding Premiere Pro utilises GPU processing power only fort certain effects, that I would never use.
    On the other hand maybe not the processor but the added video memory is key for getting constant realtime playback in a HiDPI desktop environment.
     
  6. Deanster, Nov 16, 2016
    Last edited: Nov 16, 2016

    Deanster macrumors regular

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    Jun 6, 2005
    #6
    Hopefully others can offer good advice on improving performance with your current setup.

    4K is all the rage, but editing/transcoding/rendering and storage puts truly IMMENSE pressure on your hardware. Gigabyte-per-minute file sizes push the limits of USB sticks, hard drives, playback devices, RAM, CPU's, etc. Only very fast machines can render/transcode in anything like real-time, and waiting 20 minutes to export a 10 minute clip gets old very fast.

    While it's great that your recording equipment supports it, do you really need to use 4K for this purpose?

    While I know nothing of your specific situation, from your description it sure sounds like you could do this work just as easily in 1080 or 720 and turn a workload that would essentially require a workstation-level machine to handle efficiently in 4K multi-cam into something that your laptop can handle just fine.

    Unless there's a *truly* pressing reason to be recording in 4K, I'd strongly consider setting the cameras to 720 or 1080, and then simply profit. :)
     
  7. Halbertus thread starter macrumors newbie

    Halbertus

    Joined:
    May 6, 2015
    #7
    This might be possible, but it would not fit into the current workflow. Often there is only a rather short timeframe from recording, to editing, than exporting and presenting. Probably there would not enough time to create proxy files. Also being able to zoom into more detail (mimics/gesture) from full resolution 4K video is why we use 4K video in the first place :)
    --- Post Merged, Nov 16, 2016 ---
    From a computing perspective this might be the most economic solution. A wide angle canvas in 4K resolution is very useful for detailed analysis though. Sometimes I would crop two different videos out of one 4K stream so that I can create 2 videos of different teams, that have even working next to each other in the same class-room. The bigger resolution is really nice and offers more flexibility - if you have the processing power to edit the material
     
  8. Deanster macrumors regular

    Joined:
    Jun 6, 2005
    #8
    Gotcha. That's a heck of a task for a laptop.

    Most of the people I know who are doing this sort of thing professionally moved to built super-spec Windows rigs around the time of the trash-can Mac Pro. They're running 8 or 12 cores worth of workstation CPU's, 2-3x gaming GPU's and SSD arrays over Thunderbolt 2 to get Premiere to the point where it can handle 4k multi-cam in a fairly efficient way.

    My point isn't that you're doing anything wrong, just that the features/benefits you're trying to gain aren't cheap in terms of hardware support on the back-end.

    No worries, there are a LOT of people trying to figure out how do deal with the reality of 4K footage, now that so many cameras offer the option at very reasonable prices. People don't think about how it impacts the back-end until they realize that all those extra pixels combine into a firehose that most computers just can't cope with in a time-efficient way.
     
  9. Halbertus thread starter macrumors newbie

    Halbertus

    Joined:
    May 6, 2015
    #9
    Just thought i should give a quick update on this performance issue.

    So, i could not solve the dropping frames in Premiere Pro MultiCam. Even when I transcoded the video files into a Bitrate of 8 MBits/s editing a Multicam sequence of 2 4k Videofiles would put so much stress on my Laptop, that it would throttle after short time of playback.
    I was really upset because the lack of upgrade options and expandability for my MacBook as this has been a very expensive machine and i felt it should be possible to at least make a rough edit on that machine without using any effects.

    Also I was looking to purchase a used 12-Core Xeon based classic Mac Pro Tower to get over these performance issues.

    But before spending more money on (kind of outdated hardware) I decided to try if i could get any better results with Final Cut Pro X.

    I was totally surprised seeing that in Final Cut Pro X i could edit a 4K Multicam Video of 2 camera angles running a stream of 100Mbit/s each without any problems! (CPU load of <20% !)

    This is great news for me, so maybe this information is useful to fellow community members.
     
  10. maratus, Nov 23, 2016
    Last edited: Nov 23, 2016

    maratus macrumors 6502a

    maratus

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    Canada
    #10
    Just to make sure, what was the CPU temperature and combined CPU load in all those cases?

    If you notice System power consumption in the first screenshot is around 70-75W. That means your discrete GPU is actually under load, otherwise it's impossible to reach that number. Once MBP reaches its total limit on combined power consumption power throttling is activated. It's done to not exceed AC power supply capacity and overall thermal design. The big question however is what exactly was dGPU doing in Premiere Pro
     
  11. priitv8 macrumors 68020

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    Estonia
    #11
    That would have been my next idea - to check if it may be software issue.
    Adobe may be lugging his legacy code around. Apple rewrote the FCP X from ground up AFAIK.
     
  12. Halbertus, Nov 24, 2016
    Last edited: Nov 24, 2016

    Halbertus thread starter macrumors newbie

    Halbertus

    Joined:
    May 6, 2015
    #12
    Thanks for sharing this idea. I decided to make a further comparison including 1) acticve display output devices 2) different video editing programs

    So which settings are there to compare?

    1) Integrated Display Only
    1a) Premiere Pro: High CPU Load (75%), no dropping frames
    1b) Final Cut: Low CPU Load (15%), no dropping frames

    2) External Display Only (Dell UP 2715K, 5K)
    2a) Premiere Pro: Very High CPU Load (>90%), droppings frames after a while of playback
    2b) Final Cut: Low CPU Load (15%), no dropping frames

    3) Dual Display (Integrated Display & External Display)
    3a) Premiere Pro: Very High CPU Load (>90&), dropping frames instantly
    3b) Final Cut: Low CPU Load, no dropping frames

    Details for each:

    1) Integrated Display Only // UPDATED to include total power consumption)
    1a) Premiere Pro: High CPU Load (75%), no dropping frames
    [​IMG]

    1b) Final Cut: Low CPU Load (15%), no dropping frames
    [​IMG]

    2) External Display Only (Dell UP 2715K, 5K)
    2a) Premiere Pro: Very High CPU Load (>90%), droppings frames after a while of playback
    [​IMG]
    [​IMG]

    2b) Final Cut: Low CPU Load (15%), no dropping frames
    [​IMG]

    3) Dual Display (Integrated Display & External Display)
    3a) Premiere Pro: Very High CPU Load (>90&), dropping frames instantly
    [​IMG]

    3b) Final Cut: Low CPU Load, no dropping frames
    [​IMG]
     
  13. maratus macrumors 6502a

    maratus

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    Canada
    #13
    I think it would be helpful to see System Power consumption for Case 1.
     
  14. Halbertus thread starter macrumors newbie

    Halbertus

    Joined:
    May 6, 2015
    #14
    I updated the details above in Post #12
    Although to me it seems as if the dedicated Radeon GPU is under load.
    In fact system power consumption is a lot higher when using Premiere compared to Final Cut. (while only Final Cut will allow for smooth playback.)

    From these tests it seems likely that my machine is very well capable of editing 2 streams of 4K in Multicam mode, but Adobe unfortunately do not use resources efficiently. Considering the bad playback performance one might guess that all the processing (decoding) is done in CPU and GPU is not utilised. (Then again, why is it consuming power?)

    Do you think it would help to purchase an nVidia Card connected as eGPU? Maybe Adobe Premiere is just not well optimised for AMD Radeon (OpenCL) cards.

    Unfortunately my colleagues do not own Apple computers. So switching to Final Cut is not an ideal solution because we would loose the option to exchange project files. If it was for my private use i would definately switch.
     
  15. maratus, Nov 24, 2016
    Last edited: Nov 24, 2016

    maratus macrumors 6502a

    maratus

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    Canada
    #15
    AFAIK Mac OS only supports OpenCL for GPU accelerated computing. Both applications use OpenCL, but Final Cut seems to put a bit more load on dGPU and much less load on CPU.

    Because Premiere puts a lot of load on CPU and causes power throttling of CPU (and perhaps dGPU as well) a performance drop happens. Such performance drop turned out to be enough to cause dropped frames.

    And of course it seems that Premiere is less efficient.


    OpenCL isn't GPU exclusive. It also uses specific instructions that are executed by CPU only. dGPU won't consume that much power if it wasn't being used by OpenCL. It's just that dGPU is not "enough" and a lot of work is done by CPU as well.

    I don't think it matters that much whether it's AMD or nVidia. As long as there're drivers for Mac OS and performance is acceptable you're good to go.

    eGPU should help. It'll be a videocard with more computing power and due to dGPU idling it'll prevent power throttling of the CPU. You'll get higher turbo-boost frequency under full load, perhaps higher than in 1a) case.

    Keep in mind that OpenCL acceleration by eGPU in a particular application will only work when you run the application window on a display that is connected to the eGPU.

    I think it'll be more cost effective to invest in a eGPU project. It'll give you one-of-a-kind experience too, which is fun.
     

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