linuxmemes

2 or 3 at a time normally but I'm fairly sure it could handle more depending on modpack

If you're doing it you need to get absolutely all the optimisation mods you can for the version and most importantly pregenerate the world. Once you do those things with two or 3 on it'll hover around 80% CPU usage

I will say with 4 players on Infernal Origins it struggles, I suspect because it turns up the mob spawn rate, adds custom mob AI and generates massive unlit caves everywhere for them to spawn in

On the ATM server we have 5 max upgraded apotheosis mob spawner grinders running 24/7 chunk loaded and the server's still pretty snappy still