I have been using for nearly a year now a Rapsberry PI 3 with Dietpi and PMS installed on it. I use a sd cat10 64Gb card. The media is stored to a network NAS. I have setuped all the clients to direct play (samsung Tv, several windows clients using OpenPHT, a couple of MacOSX clients using OpenPHT and 2 rasplex clients) most of the evenings the server has 2 and even 3 simultaneous clients streaming direct play.
I haven't encounter any performance problems. In fact I was very skeptical at the beggining, but today I'm impressed by how well the raspberry is able to work as a PMServer.
Still, you need to keep in mind several factors:
- DietPi is an optimized OS for raspberryPi, I have furthermore disabled bluetooth and wifi functions
- the Sd card I use is a performance one, not a cheapo one (it makes a difference, originally I used a cheapo one)
- Nothing else runs on the Pi, only the PMS, there isn't any graphical interface nor any module/program (besides ssh and PMS)
- I don't do any transcoding of any file, everything is direct play