im having no luck to improve performance on my plex server. i use a synology ds218 as it was recommended as a starter server. is there anything i can do outside of the server to improve performance like say i eant to use my server outside my home at another Xbox/firestick?
No, this model is not made for Plex transcoding. But it can be used for 4K via DS Video app. You get an Android TV HDMI stick and install this app.
Otherwise, if you still prefer Plex there is something you can do. Convert every video into 560p or 720p videos depending on your internet upload speeds. Plex will automatically play this file if the original file is too big. Plex also has built in file optimise function.
I hope this helps.