ChunkyFast

ChunkyFast is a high-performance chunk pregenerator for Paper 1.21.x. It provides a clean, predictable workflow for pregenerating terrain, supports running multiple world jobs in parallel, and includes built-in scheduling and load control.

Key Features

• Async chunk generation using Paper’s async chunk API
• Multi-world pregeneration: run jobs for multiple worlds at the same time
• Global scheduler: shared budgets across all active jobs so load does not scale linearly with the number of worlds
• MSPT-based limiter: dynamically adjusts throughput to keep average tick time near your configured target
• Region-friendly traversal: chunk iteration optimized for better region (.mca) locality
• Optional skipping of already-generated chunks using region header scanning (fast, non-blocking)
• Auto-save + auto-resume: job state is persisted and can resume after restart
• MiniMessage formatting for all plugin messages

Supported Versions

• Paper: 1.21.x
• Java: 21+

Installation

1. Download the latest release from GitHub Releases.
2. Put ChunkyFast.jar into your server plugins/ folder.
3. Start the server once to generate the default config.
4. Adjust plugins/ChunkyFast/config.yml if needed.
5. Use the commands below.

Commands

Main command: /chunkyfast
Aliases: /cf, /cfast

Start pregeneration

All coordinates and radii are in CHUNKS (not blocks).

/chunkyfast start <world> circle <radiusChunks> [centerX centerZ]

/chunkyfast start <world> square <radiusChunks> [centerX centerZ]

/chunkyfast start <world> rect <minX> <minZ> <maxX> <maxZ>

/chunkyfast start <world> worldborder

How ChunkyFast Differs From Chunky

ChunkyFast and Chunky aim at the same outcome (pregenerating terrain), but they emphasize different things.

ChunkyFast focuses on

• Multi-world parallel jobs with a global scheduler
• MSPT-driven throughput control (limiter adjusts workload to keep tick time stable)
• A lean workflow with minimal overhead
• Optional non-blocking “already generated” detection via region header scanning

Chunky focuses on

• A long-established, highly feature-rich pregeneration ecosystem
• Extremely broad configuration and safety controls
• Mature workflows for a wide variety of server environments

Practical takeaway: ChunkyFast is built around multi-world scheduling and MSPT-based control, while Chunky is a feature-complete, widely adopted solution with deep tooling and history.

Notes

• Pregeneration speed is typically limited by CPU world generation and disk I/O for region writes.
• For best results, run pregeneration when the server has enough resources available.