I'm hoping a Mac upgrade would solve the problem. Will upgrading to the latest 2020-era 16' fully spec'd MacBook Pro (2TB SSD + 32GB RAM) eliminate the buffering issue when delivering 4k content from Plex Server to AppleTV? Is there a way for novice consumers like me to figure this out on their own by looking at the more modern Mac's specs? It feels like my current 2015 machine is almost powerful enough to do it, but not quite. The problem can be eliminated by telling the Plex client to play the content at 1080p instead of 4k but I much prefer the visual quality of 4k. After a few seconds the error message disappears and the movie resumes at full quality. Plex shows a temporary error popup indicating that either the network is too slow or the CPU on the Plex server isn't powerful enough to convert the file. Once every five minutes or so the movie freezes. The 4k video quality is absolutely beautiful and audio is fantastic too. Both the Mac and the AppleTV are hardwired to the network via 1gb Ethernet.

The AppleTV is connected to a 72' Sony OLED TV where I view the content. Plex Server runs on the Mac and the Plex Client runs on the AppleTV. I use a program called Plex to stream the movies from the MacBook to an AppleTV.

I've downloaded some 4k movies to that computer. I have a mid-2015 MacBook Pro running 10.15.3.

Plex server mac