INTERACT FORUM

Devices => Video Cards, Monitors, Televisions, and Projectors => Topic started by: Manfred on May 23, 2021, 10:12:52 am

Title: 100 % CPU load 8k HDR 60 FPS
Post by: Manfred on May 23, 2021, 10:12:52 am

If playing

https://www.youtube.com/watch?v=hVvEISFw9w0 (https://www.youtube.com/watch?v=hVvEISFw9w0)
locally with RO HQ i7 4C4T goes to 100% utilization whereas GPU on GTX 1070 8GB is only 21%.

File Type is .webm
movie is 3840x2160 HDR 1100 nits, BT2020->custom gamut, primaries BT.2020, chroma > Jinc AR, image < BC150 LLAR, P010, 10 bit 4:2:0

HDR in madVr is  configured as: use pixel shader math

Why is CPU high and GPU low?

If playing same video direct in MS Edge from YouTube side: CPU: 21% GPU: 51% 

Title: Re: 100 % CPU load 8k HDR 60 FPS
Post by: Manfred on May 24, 2021, 04:06:27 am

I think I got it: GTX 1070 does not support 10 bit V9 (.webm) HW decoding. Only 8 bit.

Converting it with MC to H264 ->colours get washed out. Best playback is to use Edge.

Title: Re: 100 % CPU load 8k HDR 60 FPS
Post by: tij on May 27, 2021, 02:05:37 am

I dont think thats it ... if your GPU did not support vp9 10bit ... playing video through Edge would have caused 100% CPU load too for decoding.

Since Edge does not use 100% cpu ... it is somehow using your GPU to decode it ...

Maybe MC is wrongly recognising your GPU as not capable of decoding VP9?

Title: Re: 100 % CPU load 8k HDR 60 FPS
Post by: Manfred on May 27, 2021, 08:21:43 am

Ok-: Edge has something like madVR CTRL-J, it says its playing BT.709 which means that it has mapped 10bit ->8bit. 8bit/VP9 is supported by GTX1070. That would mean Edge has done some Colour and bitdepth mapping internally. Edge uses the GPU - one sees that in MS task manager.

So MC is correct.

Title: Re: 100 % CPU load 8k HDR 60 FPS
Post by: tij on May 27, 2021, 09:09:52 am

No way edge can transcode vp9 without heavy cpu usage if hardware decoding is not available ... very likely it negotiated with yourube to receive h265 or h264.

According to this https://en.m.wikipedia.org/wiki/Nvidia_PureVideo
1070 supports 10 bit vp9 decoding (not encodimg)

So maybe MC is not utilizing this feature for greater compatibility? (Maybe AMD gpu dont support vp9 decodimg?) ... just shhoting in the dark here

Title: Re: 100 % CPU load 8k HDR 60 FPS
Post by: Manfred on May 27, 2021, 10:29:36 am

NVIDIA says's no to VP9 decoding 10 bit with GTX 1070:

https://developer.nvidia.com/video-encode-and-decode-gpu-support-matrix-new#Encoder (https://developer.nvidia.com/video-encode-and-decode-gpu-support-matrix-new#Encoder)

Title: Re: 100 % CPU load 8k HDR 60 FPS
Post by: tij on May 27, 2021, 09:47:44 pm

Funny how 1030 and 1050 supports but 1080 and 1070 dont lol

Title: Re: 100 % CPU load 8k HDR 60 FPS
Post by: Hendrik on May 28, 2021, 12:38:11 am

The 1060, 1070 and 1080 were just the first to come out, the others came later and the capability was added in the newer cards - even if the same generation.