When a player explores new territory, your server has to generate brand new chunks in real time. This is one of the most CPU-intensive operations in Minecraft, and on a busy server it can tank the TPS for everyone.
Installing Chunky
Chunky is the best chunk pre-generation plugin for modern Minecraft. Download it for Paper/Purpur and drop it in your plugins folder.
Basic usage:
/chunky radius 5000
/chunky start
This pre-generates a 5000-block radius from spawn (10,000 x 10,000 total area). For most servers, this covers the playable area.
Recommended Radius by Server Type
| Server Type | Recommended Radius | Chunks Generated | Storage Used |
|---|---|---|---|
| Small SMP (5-10) | 3,000 | ~14,000 | ~2GB |
| Medium Server (20-50) | 5,000 | ~39,000 | ~5GB |
| Large Server (50+) | 8,000 | ~100,000 | ~12GB |
| Minigame Lobby | 500 | ~400 | ~50MB |
For modded servers, plan for higher storage. Modded world generation creates larger chunk files due to custom ores, structures, and biomes.
Running the Pre-Generation
Pre-generation uses significant CPU. Here's how to do it without disrupting players:
Option 1: Pre-generate before opening the server
The best approach. Run Chunky on your empty server, let it finish, then open to players. Zero impact on gameplay.
Option 2: Throttle during live play
/chunky continue
/chunky pause
Run generation during off-peak hours and pause it when players are online. Chunky remembers its progress and resumes where it left off.
Performance Results
On a Space-Node Minecraft server running the Ryzen 9 7950X3D:
| Scenario | TPS Without Pre-Gen | TPS With Pre-Gen |
|---|---|---|
| 20 players, vanilla | 18.5 | 20.0 |
| 20 players, 5 exploring | 15.2 | 19.8 |
| 10 players, ATM10 | 16.8 | 19.3 |
The difference is most dramatic when multiple players explore simultaneously. Without pre-generation, each exploring player competes for the same CPU resources. With pre-generation, chunk loading becomes a simple disk read instead of a heavy computation.
Nether and End
Don't forget the other dimensions. Nether chunk generation is faster but still causes lag:
/chunky world world_nether
/chunky radius 2000
/chunky start
The End dimension usually doesn't need pre-generation unless you have custom End content. The main End island generates quickly, and the outer islands are typically explored slowly.
Maintaining Your Pre-Generated World
After a Minecraft update that changes world generation, newly generated chunks at the border of your pre-gen area will have visible chunk borders. This is normal and unavoidable.
Solutions:
- Extend your pre-gen radius after major updates to push the border further out
- Use WorldBorder to limit exploration to your pre-generated area
- Accept the chunk borders as a natural part of progressive updates
Pre-generating your world costs an hour or two of CPU time upfront and rewards you with months of lag-free gameplay.
