A Minecraft server lags when it cannot compute its 20 ticks per second (TPS). The usual causes are new chunk generation, too many entities, a heavy plugin or mod and a view distance that is too large. Measure before paying for more RAM.
Step 1: server lag or network lag?
- Server lag: everyone feels it, the console shows
Can't keep up!, TPS under 20. - Network lag: one player only, high ping.
- Client lag (low FPS): their PC.
Type tps on Paper: 20 is perfect, below 15 is a real problem.
Step 2: find the culprit with spark
At Artaun: Settings > Toolbox > Measure performance installs spark. Restart, run spark profiler start, wait a few minutes, spark profiler stop, open the link.
Common causes
- Chunk generation: pre-generate with Chunky and set a world border.
- Too many entities: limit farms and tune Paper entity limits.
- Distances: in Settings > Server settings try View distance 8 to 10 and Simulation distance 6 to 8.
- A bad plugin or mod: update it or disable it from Game tools.
- Server type: Paper (or Fabric with Lithium) is much faster than Vanilla.
- Memory: if the RAM curve stays below 70%, it is not memory.
- CPU: Minecraft is mostly single-core, so frequency matters. Our Extreme range uses Xeon Gold 6248R up to 4 GHz; Eco uses Xeon Gold 6230.
A routine that avoids most lag
Nightly restart (More options > Automatic tasks), pre-generated map, sane simulation distance, updated plugins.
FAQ
Will more RAM fix lag? Only if the server lacks memory.
It lags only in the evening. The Statistics page shows hourly attendance: compare with TPS drops.
See the Minecraft server plans.