MP 1,1-5,1 5700xt + Catalina vp9 8k decoding?

[startergo]

Does it matter that my GPU is in slot-2?

Do you have HWA enabled? for the second slot you need -wegtree boot argument in OC.

 

[Pressure]

 

[startergo]

Now this make sense to me based on the tests so far:

Polaris supports hybrid VP9 decode(it utilizes the "3D" section in Windows Taskmanager) but the performance is quite good over the time with driver updates. Do make sure that you have updated your driver to the newest one and use a proper browser with hardware acceleration enabled.(FireFox got excellent VP9 implementation compared to Chrome.)

Plus,video buffering actually eats up your CPU resource quite a bit so make sure the video had been fully buffered before testing.

https://www.reddit.com/r/Amd/comments/bno6bw

 

[Pressure]

Now this make sense to me based on the tests so far:

The Polaris driver also appears to be much more polished in macOS.

 

[jasonmvp]

Just for giggles, now that I have some time in front of my 7,1 with Chrome:

Easy peazy in 60FPS for me. It does send the Xeon to ~33% utilization of course. And that's pretty much across all cores. If I put the window in the background, like when I'm writing this post and trying to play it simultaneously, I do get a couple of stutters. Otherwise, smooth as silk.

And all CPU-bound.

 

[CMMChris]

Radeon VII + i7-8700K running as iMacPro1,1 playing 8k60 footage on YouTube.

CPU does all the work. There is no VP9 acceleration in macOS and it doesn't matter which GPU you use. Apple simply hasn't implemented it, period. All they support is H.264 and H.265 aka HEVC. If I put additional workload on the CPU it starts dropping frames. If I put additional load on the GPU it does not drop frames.

On Windows VP9 GPU acceleration works fine and decoder load is even displayed in the task manager. If I put load on the CPU while playing, no dropped frames. If I tax the GPU while playing, it starts to drop frames. Exactly the (expected) opposite of macOS as logic suggests.