Entity Tick Optimizer

High-performance Fabric mod for Minecraft 1.21.11+ that reduces CPU usage by intelligently throttling entity AI ticking for mobs that are far from players.

Features

• Activation Range Throttling: Mobs beyond configurable distances from the nearest player have their expensive goal selectors, target selectors, and navigation completely skipped every tick.
• Category-specific ranges: Separate distances for monsters, animals, ambient, water creatures, etc.
• Very low overhead: Uses efficient Level.getNearestPlayer checks only when needed.
• Fully configurable via config/entity-tick-optimizer.json (auto-generated on first run).

Recommended Settings (defaults)

• Monsters: 48 blocks
• Creatures (animals): 32 blocks
• Ambient: 16 blocks
• Water creatures: 32 blocks

On a busy server these defaults can save 30-70%+ of entity-related CPU time.

Requirements

• JDK 21 (Minecraft 1.21+ requires Java 21 to build and run)
• Fabric Loader + Fabric API (for the target Minecraft version)

Important: Set JAVA_HOME to your JDK 21 installation before building, or use a Gradle wrapper that detects it.

Common install locations after using winget/Adoptium:

• C:\Program Files\Eclipse Adoptium\jdk-21.0.x.x
• C:\Program Files\Java\jdk-21

Building

# Set JAVA_HOME first (example)
$env:JAVA_HOME = "C:\Program Files\Eclipse Adoptium\jdk-21.0.7.6-hotspot"
.\gradlew.bat build

The built jar will be in build/libs/.

License

MIT License. Feel free to use and modify.