Memory is the first thing people buy more of and often the last thing that was actually wrong. It fixes one specific class of problem completely, and does nothing at all for the others.
Why it happens
Minecraft's tick runs on a single thread. Memory determines how much can be loaded at once — world data, plugins, mods — but not how fast it is processed. A server with plenty of free memory can still sit at 12 TPS, because the bottleneck is time inside the tick, not space.
What to do
- More RAM fixes: out-of-memory crashes
If the console ends with
java.lang.OutOfMemoryErroror the container is killed, you are genuinely out. That is the case where a bigger plan solves it outright. - More RAM fixes: large modpacks that will not start
Modpacks load everything at boot. A pack that needs 6 GB will simply not start in 4, no matter how few players you have.
- More RAM does not fix: low TPS with memory to spare
If
/spark heapsummaryshows plenty of headroom and TPS is still low, the problem is entities, a plugin or view distance. Adding memory changes nothing. - Rough starting points
Vanilla or light plugins with a handful of friends: 2–4 GB. A plugin server with 20 players: 6–8 GB. A hundred-mod pack: 8–12 GB. Kitchen-sink packs like All The Mods: 12–16 GB and up.
Before upgrading, confirm with /spark heapsummary that memory is actually the constraint. If it is not, you would be paying for something that was never the limit.
Our calculator asks about your modpack, players and render distance and picks a plan from the same numbers used here.