In my experience, a machine with a 15-year-old processor stuttered a lot with three players connected and became pretty unplayable with more. Valheim isn't too demanding a game, and neither is running a server, but combined, they'll put a strain on most machines-and on the connection quality for other players.
Things to consider are the speed of your internet connection and how powerful your gaming PC is. Some will put it on a secondary computer, others on the same machine on which they're going to play. You can put up a dedicated server on any PC. (Image credit: Iron Gate AB) Where to host a Valheim dedicated server
