From: Michael Galea via talk <talk@gtalug.org>
I did consider the PI when both v3 and v4 came out. The V3 was a no go from the start, and with V4 I noticed stuttering and tearing. I wonder why your experience seems to be better than mine.
RPi 4 should be fine: it has a hardware HEVC decoder. It handles up to 4k @ 60 Hz. Of course your software might not be using it. You might need to enable it at boot. See this link for enabling the hardware. It's up to Myth code to use it. <https://forums.raspberrypi.com/viewtopic.php?t=323303> (Note: I've never done this. I just google.)
One thing Ive noticed, and have to fix, is that HEVC encoded content seems to be burdening my existing CPU, often to the point where it overheats and shuts down.
I think "Existing CPU" = some x86 PC plus an old Nvidia card. Am I correct? Intel has "Quick Sync Video". That seems to be hardware assist for some CoDecs. <https://en.wikipedia.org/wiki/Intel_Quick_Sync_Video> Newer processors have more CoDecs. I imagine that it is well exploited for playback. HEVC decoding was part of Quick Sync for some time. I am even less familiar with AMD's equivalent. According to Wikipedia, the names to look for are Unified Video Decoder and later Video Core Next.