I am planning on moving my PMS from an old laptop to a NUC or similar. My use case is fairly narrow. Maybe two streams, 1080p at most, direct play usually, but I would like to be able to transcode to burn in DVD subtitles (my Roku can’t direct play them).
This machine will also do a few other household odds-and-ends, so I don’t want to just use a NAS.
I’m thinking of using a NUC8i3BEH1 with 16GB ram, a 250GB SSD and a 4TB hard drive.
This should work for your use case, as long as you are not getting into H.265/HEVC codec.
If you do, you’ll have to get a Plex Pass, in order to be able to use the hardware transcoder in Plex.
I got almost the same setup. Got the NUC8i3BEK version with 8GB ram and plex pass. Using ubuntu server 18.04. Latest version of plexmediaserver reports (wrongfully) that the cpu is not strong enough for transcoding however. All previous versions worked flawlessly.