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Mods › FastChunkGen

FastChunkGen

FastChunkGen is a unofficial forge port of C2ME with fixes, stability and performance improvements.

34 config settings

Build 0.1.4 · checked 13 September 2026

Guides

Config

  • Chunk IO Thread Fixes chunkIoThreadingIssues fixes — Fix thread-safety issues in vanilla chunk IO.
  • Faster Shutdown disableLoggingShutdownHook fixes — Remove the log4j2 shutdown hook and force exit if a dedicated server hangs.
  • Strict Random Access enforceSafeWorldRandomAccess fixes — Crash instead of warn when something uses the world random off-thread. For debugging.
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  • Chunk System Thread Fixes generalThreadingIssues fixes — Fix thread-safety issues in the vanilla chunk system.
  • Vanilla World Gen Bug Fixes vanillaWorldGenBugs fixes — Fix vanilla world generation bugs.
  • World Gen Thread Fixes worldGenThreadingIssues fixes — Fix thread-safety issues in vanilla world generation. Required by threaded world generation.
  • Auto Save Delay delay generalOptimizations — Milliseconds before a dirty chunk is auto-saved. Enhanced mode only.
  • Auto Save Mode mode generalOptimizations — Vanilla saves every tick, Enhanced saves during idle time, Periodic saves every 6000 ticks.
  • Mid Tick Chunk Tasks midTickChunkTasksInterval generalOptimizations — Nanoseconds between chunk tasks run inside the tick loop.
  • Async Chunk Requests optimizeAsyncChunkRequest generalOptimizations — Serve off-thread chunk requests without blocking the server thread.
  • Optimize Scheduling optimizeScheduling generalOptimizations — Optimize chunk task scheduling.
  • Override ModernFix Allocations overrideModernFixWorldGenAllocations generalOptimizations — Apply our world generation allocation patches ahead of ModernFix's equivalent ones.
  • Reduce Allocations reduceAllocations generalOptimizations — Reduce allocations in hot paths.
  • Worker Threads globalExecutorParallelism — Worker threads used for chunk generation and IO.
  • Async Chunk IO async ioSystem — Load and unload chunks off the server thread.
  • Chunk Cache Hard Limit chunkDataCacheLimit ioSystem — Hard cap on cached chunk writes.
  • Chunk Cache Soft Limit chunkDataCacheSoftLimit ioSystem — Cached chunk writes before flushing to disk starts.
  • Chunk Compression chunkStreamVersion ioSystem — Compression for newly saved chunks. -1 vanilla, 1 GZip, 2 Zlib, 3 none.
  • Fire Chunk Data Events fireForgeChunkDataEvents ioSystem — Fire Forge ChunkDataEvent.Save on async saves. Off means mods lose per-chunk data.
  • Chunk Data Events On Server Thread forgeChunkDataEventsOnMainThread ioSystem — Fire Forge chunk data events on the server thread. Off is unsafe for most mods.
  • GC Free Chunk Serializer gcFreeChunkSerializer ioSystem — Allocation free chunk writer. Cannot fire Forge chunk data events, so mods lose per-chunk data.
  • Chunk IO Optimizations optimizations ioSystem — Enable chunk IO optimizations.
  • Recover From Errors recoverFromErrors ioSystem — Regenerate chunks that fail to load. Destroys their contents.
  • Rewritten IO replaceImpl ioSystem — Use the rewritten chunk IO implementation.
  • Safe Block Entity Saving serializeBlockEntitiesOnMainThread ioSystem — Snapshot block entity data on the server thread. Turning this off is faster but can corrupt modded block entities.
  • Threaded Lighting enabled threadedLighting — Run light updates on a dedicated thread.
  • Threaded Features allowThreadedFeatures threadedWorldGen — Generate features like trees, ores and structures in parallel.
  • Async Scheduling asyncScheduling threadedWorldGen — Schedule generation tasks off the server thread.
  • Threaded World Generation enabled threadedWorldGen — Generate chunks on multiple threads.
  • Reduced Lock Radius reduceLockRadius threadedWorldGen — Lock fewer neighbouring chunks per generation step for more parallelism.
  • Vanilla World Gen Optimizations enabled vanillaWorldGenOptimizations — Optimize vanilla world generation.
  • Faster Aquifers optimizeAquifer vanillaWorldGenOptimizations — Faster aquifer sampling.
  • Cheaper Random Instances optimizeRandomInstances vanillaWorldGenOptimizations — Cheaper random instances during world generation.
  • End Biome Cache useEndBiomeCache vanillaWorldGenOptimizations — Cache End biome lookups.

Frequently Asked Questions

How does FastChunkGen improve chunk generation performance?

It moves chunk generation, feature population, and lighting calculations onto multiple background worker threads instead of running them on the main game loop.

What does Threaded Lighting do in FastChunkGen?

Threaded Lighting shifts light updates to a dedicated thread, preventing light calculations from stalling terrain generation.

How does Auto Save Mode work in FastChunkGen?

Auto Save Mode lets you adjust chunk saving behavior between standard per-tick saving, saving during server idle time, or saving periodically every six thousand ticks.

Why should Safe Block Entity Saving remain enabled?

Safe Block Entity Saving takes clean snapshots of block entity data on the server thread before saving to prevent corrupting modded storage containers or machines.

Download Links

Mods › FastChunkGen