Je 4 GB RAM pro Minecraft v pořádku?

Yes, this is by far enough ram to run Minecraft. I spent about 4 years on a machine with 4gb RAM, and I can assure you that the only issue with that amount of RAM is trying to do more things at the same time (chrome + game for example), but even then the main issue with Minecraft is the graphics.

Kolik RAM na Minecraft server?

( https://hostify.cz/minecraft/ ). ty požadavky tam jsou nesmyslný (a nebo hodně starý). Dnešní server s pár pluginama potřebuje pro 3-4 hráče a pohodlný hraní min 2GB RAM.