I am trying to play a 4k video on the same machine the media is hosted on. I can play the video fine outside of plex, but within plex it is constantly buffering and stopping play. My CPU is a Ryzen 5600 and never goes above 50% utilization, my GPU (RTX 2080) is also barely used when trying to play back the video. I’ve searched for similar issues and have tried updating all my drivers and even moved the media to my m.2 drive, subtitles are off, hardware acceleration is on, none of which helped in any way.
Any suggestions would be appreciated. Thanks
UPDATE: Disabling HDR tone mapping, fixes the buffering issue but video quality is unwatchable…
What player are you using? I find that using something widely available and with good support is very helpful, so I start using VLC (whatever my preferred player is). What is your player? Web browsers tend to have a tough time, for what it is worth.
If you want a big screen TV layout (like TV Mode in Plex Media Player), try Plex HTPC, the new client for home theater PCs.
Your system is transcoding the video.
Transcoding video can use hardware acceleration via the RTX 2080. However, HDR tonemapping on Windows does not support Nvidia GPUs and will occur on the CPU. HDR tonemapping is also a preview feature, so even with a powerful processor such as a Ryzen 5600 it may not work well.
Plex Web cannot direct play HEVC video due to web browser limitations.
Plex for Windows (PfW) is a more capable client than Plex Web. PfW uses mpv.io as the underlying video player. It can scale 4K video to lower resolutions and tonemap HDR to SDR without involving Plex Media Server. As a result, using PfW, you can direct play 4K HDR media when using a 1080p SDR display.
If you do try Plex for Windows, check Settings → Plex for Windows → Player (Show Advanced). In the video section you can adjust Video Playback Quality and also enable Hardware Decoding. Higher quality settings use more system resources (CPU, RAM, etc). Hardware Decoding lets Plex for Windows decode video using your Nvidia GPU instead of the CPU.
Sort of found a solution. It appears Plex for windows doesn’t support HDR tone mapping at all but Plex Media Player does and gets rid of the lag completely.
