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Nintendo Maniac 64 · 14th September 2018, 08:23

I just did some performance testing with the 1080p 30fps AV1 encode of the Gus Kenworthy & Tom Wallisch X Games Slopestyle GoPro Preview video in MPC-HC v1.8.1 x64 with its built-in LAVfilters; I originally tried the Halo video but I found the X Games video to be much more demanding (but also much more motion-sick inducing, especially when playing at slower than real-time).

With my 4c/8t Nehalem Xeon x3470 I was only seeing ~25% CPU utilization at maximum even though I was unable to play back the video in real-time (it was somewhere between 16fps and 20fps). Mathematically that should mean that it's only using 2 threads, but disabling SMT and setting my BIOS to only enable 2 cores resulted in noticably worse performance, yet setting the BIOS to enable 3 cores without SMT resulted in the same 16-20fps performance I was originally seeing yet at only ~67% CPU utilization.

At least with the LAVfilters bundled with MPC-HC v1.8.1 x64, it would seem that the AV1 decoder can only utilize 3 cores and no SMT, yet even then the 2 less loaded cores are only hitting around half of their according core's available utilization.

And for reference, the 720p 30fps AV1 encode of that same video played back without a hitch on my Xeon - heck it left enough headroom that I could turn on a bunch of motion interpolation which greatly helped alleviate the motion sickness I got from watching the 1080p AV1 encode playback at sub-20fps frame rates (it's times like this that I thank the devs over at Nintendo for making F-Zero X and F-Zero GX native 60fps games).

Now I'm a bit out-of-the-loop, but I couldn't help but notice that YouTube-DL was using the .MP4 extension for AV1 downloads - is that in fact correct behavior? (and no, I don't mean AVC1, otherwise my PC would have been playing back the videos easy-peasy).

14th September 2018, 08:23	#940 \| Link
Nintendo Maniac 64 Registered User Join Date: Nov 2009 Location: Northeast Ohio Posts: 447	I just did some performance testing with the 1080p 30fps AV1 encode of the Gus Kenworthy & Tom Wallisch X Games Slopestyle GoPro Preview video in MPC-HC v1.8.1 x64 with its built-in LAVfilters; I originally tried the Halo video but I found the X Games video to be much more demanding (but also much more motion-sick inducing, especially when playing at slower than real-time). With my 4c/8t Nehalem Xeon x3470 I was only seeing ~25% CPU utilization at maximum even though I was unable to play back the video in real-time (it was somewhere between 16fps and 20fps). Mathematically that should mean that it's only using 2 threads, but disabling SMT and setting my BIOS to only enable 2 cores resulted in noticably worse performance, yet setting the BIOS to enable 3 cores without SMT resulted in the same 16-20fps performance I was originally seeing yet at only ~67% CPU utilization. At least with the LAVfilters bundled with MPC-HC v1.8.1 x64, it would seem that the AV1 decoder can only utilize 3 cores and no SMT, yet even then the 2 less loaded cores are only hitting around half of their according core's available utilization. And for reference, the 720p 30fps AV1 encode of that same video played back without a hitch on my Xeon - heck it left enough headroom that I could turn on a bunch of motion interpolation which greatly helped alleviate the motion sickness I got from watching the 1080p AV1 encode playback at sub-20fps frame rates (it's times like this that I thank the devs over at Nintendo for making F-Zero X and F-Zero GX native 60fps games). Now I'm a bit out-of-the-loop, but I couldn't help but notice that YouTube-DL was using the .MP4 extension for AV1 downloads - is that in fact correct behavior? (and no, I don't mean AVC1, otherwise my PC would have been playing back the videos easy-peasy). Last edited by Nintendo Maniac 64; 14th September 2018 at 09:15.