iMac Pro 4K HEVC Massive Stutter - iMac Pro 2017 - 8 Core - Vega 56, 32GB RAM

[Chrisjmv]

Hey guys, I have send some of my 4k 60FPS iPhone 12 Pro Max Videos to my iMac Pro (8 Core, Vega 56, 32GB Ram, 1TB SSD running Big Sur) and its dropping frames and running choppy.

then i Tried to play this file here from Sony 4k HEVC .mp4 and sound is running but picture is running like 1-2 FPS.

Google Drive - Virus scan warning

drive.google.com

CPU Usage is like 10-20% and GPU also low... what is that???


isnt the iMac Pro 2017 not compatible with HEVC Material?

never noticed that before, or is it a problem with Mac OS Big Sur?

 

[masotime]

Could be a player issue - I’ve found IINA to be more performant when trying to play back some HEVC content - https://iina.io/

 

[Chrisjmv]

when I reboot my iMac Pro everything is fine, as soon as the Screensaver kicks in, my Radeon 56 clocks down to 19MHZ and doesn't use more clock speed when playing HEVC Content.. so it seems like a Power State issue?

 

[Chrisjmv]

No one Any idea?

 

[dewalt23]

I have the exact same issue, were you able to resolve it?

 

[Chrisjmv]

For me nothing. I don’t think so Apple will fix this - they also now discontinue the iMac Pro on sale