Hi, I am not really sure. I am making a Factions Server, its going to have at least 4 worlds. Many hosts say that more RAM better performance... but for Factions is this the case? Or is it judged on CPU for example my host has 4.5 GHz of CPU. But only 1024 MB ram. Would this be good to host with 20 playerrs online simetaneously (ugh i cant spell today xD) @KittyDev
20 players online with 1024 MB ram is more than sufficient. RAM is random access memory, it won't make your server performance better. You are looking for a better CPU. You do of course need sufficient RAM, but the amounts offered are often more than you actually need.
So, how much players can I run comfotably. Note some players are pvping in another world. Some mining. Some building. And some hacking ofc.
There's no exact number, as has been said before: https://forums.pmmp.io/threads/recomend-player-slots-per-1-gig-of-ram.3861/#post-36790
I must add here that RAM was playing a role when PocketMine (and forks) had many memory leaks. Today I'm always happy to see the same small amount of used memory when executing the status command - no matter how long the server is running. So many thanks to @dktapps using his time and skills to improve the quality and reliability of pmmp!
General rule of thumb: Look for best CPU performance over lots of memory - you don't need lots of RAM. Prefer high GHz per core, and you don't need ridiculous numbers of cores - 2 or 4 should do fine. 4.5GHz will do fine.