Casting 4K from phone causes stuttering, but works great casting from PC



I recently came upon this issue after I got my Chromecast Ultra and downloaded some 4K movies. I noticed they were all stuttering and buffering constantly, to the point that it was unwatchable. I tried a bunch of suggestions I found here, but none of them worked. Looking at the Task Manager on the PC running the server, I also noticed the PlexTranscoder was taking up 75% of my CPU power!

On a whim, I tried casting from a browser on that same PC. No buffer or stuttering, beautiful 4K video, and Task Manager shows maybe 2% usage for the Transcoder.

Why does this happen? Is there anything I can do to fix this without sacrificing quality?


If you're casting from an Android phone then for some reason Plex seems to transcode by default even if you have it set to play original quality by default. The way to fix it is to start playing the video and then manually set the quality to Original. I've noticed that it doesn't always work and I sometimes have to try changing it multiple times.


+1, same problem. I've only experienced it with EAC3 audio though.