foxlucas
Level 1 (0 points)

Q: Compression 4.2 GPU Acceleration?

Release notes for Compressor 4.2 contains the following in its list of improvements:

 

"GPU rendering when using Send to Compressor with support for dual GPUs"

"Hardware-accelerated multi-pass H.264 encoding on compatible systems"

 

My system is:

 

Mac Pro (late 2013)

3.5 GHz 6-Core Intel Xenon E5

16 GB 1866 MHz DDR3 ECC

AMD FirePro D700 6144 MB (Dual)

Apple Thunderbolt Display (one 27")

1 TB Flash Storage (Half full)

 

Video processing performed in FCPX 10.2 with video from multiple Canon XA20's 1920x1080[ at 24fps

 

The edited video is Sent to Compressor and converted to 1280 x 720p H.264 using the multi-pass option.

 

Although the output has been split into more than one file during processing (something has changed), there has been no reduction in processing time for these videos.  A 20 minute video compressed in 25 minutes or so.  If the same video is compressed to 1920 x 1080p (the original format) it takes over 50 minutes.

 

Does my system fail to meet the requirements?  Does the increased performance promise only apply to a specific set of compression settings?

 

Any help you can provide will be greatly appreciated.

 

Thanks.

iCloud, Mac OS X (10.7.5)

Posted on May 10, 2015 5:14 PM

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foxlucas

Q: Compression 4.2 GPU Acceleration?

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  • Helpful answers

  • by Russ H,

    Russ H Russ H May 10, 2015 7:47 PM in response to foxlucas
    Level 7 (21,905 points)
    Quicktime
    May 10, 2015 7:47 PM in response to foxlucas

    I know that recent (past 3 years)  MPB and iMacs have CPUs with  Quick Sync and they support hardware acceleration, But I'm bot sure about the  Mac Pro. Perhaps someone else who knows for sure will chime in.


    It's surprising that an en encode without scaling would take longer than one with scaling.

     

     

     

    Russ

  • by BenB,

    BenB BenB May 16, 2015 5:09 AM in response to Russ H
    Level 6 (10,041 points)
    Audio
    May 16, 2015 5:09 AM in response to Russ H

    Only the i5 and i7 GPUs have the H.264 hardware acceleration, which your nMP doesn't have, and it was actually released in the previous version of Compressor.  Not sure why they repeated it in the current release notes.  That happens sometimes.  And it is only for single-pass operations.

     

    No, splitting the video up into various files during processing is not new, just that with Yosemite you can see them in the Finder now, they're supposed to be hidden during processing.  That's a bug.

     

    Encoding times can vary depending on what it taking place.  Going 1920 to 720 is simply throwing away data, so less data is actually being written, than if you kept it 1920.  So the difference makes sense.  Try single-pass to get better speeds, and I bet you don't see any image quality differences.

  • by Fred Turner,Helpful

    Fred Turner Fred Turner May 18, 2015 8:05 PM in response to BenB
    Level 1 (85 points)
    May 18, 2015 8:05 PM in response to BenB

    and it was actually released in the previous version of Compressor.  Not sure why they repeated it in the current release notes.  That happens sometimes. And it is only for single-pass operations.

     

    Actually, the release notes do specifically say "multi-pass H.264 encoding on compatible systems" (not just single-pass). And testers have been seeing some significant speedups w/ Compressor 4.2 vs. 4.1. So something has indeed changed. I'm curious what falls under "compatible systems" though...can't seem to locate that so far. Since Quick Sync is hardware-based, and therefore not changeable, I wonder if this multi-pass acceleration is something else, perhaps GPU-specific.