I am developing an 1vs1 minigame. Now I'm asking myself the question, if I should create one world per two players or if I should have one world for 50 players. Does someone know which option has better performance?
1 world for 50 players. If the players are on the same world, there are less chunks loaded so less RAM in use. The only bad thing is that this would cause client lag, so you if you have a lot of RAM and your plugins are not laggy, use the 1 world per 2 players.
I had a tough decision on a similar issue. When working on a PvP server, I had to recreate a randomly chosen arena dedicated for the two players/parties, so I went with this method: Create a world named "temp" on plugin enable. This is a "void" world — it has no terrain generation. When a game starts, copy and paste a schematic of the arena. Delete the world on plugin disable. I made an (arguably) efficient runtime "schematic" class for a minigame plugin some months ago... mmm not the best but it gets the job done. It gets pasted at every arena_length+4chunks along the X coordinate so you have a never ending row of infinitely-generating arenas along the X axis. That way you could have a lot of players in the same world and still not crumple things up and maintain the flow.