Minecraft server mods and optimization for performance

Low TPS comes from high view-distance, uncontrolled farms, heavy plugins or a weak CPU. This guide collects settings that work on Paper, Purpur and Forge/NeoForge modpacks.

TPS and MSPT

Paper and Purpur

Paper already optimizes on top of Spigot. Purpur inherits that and adds options in purpur.yml. Lower simulation-distance separately from view-distance: players see far, the server simulates less.

entities:
  spawning:
    alt-item-despawn-rate:
      enabled: true
      items:
        cobblestone: 300
    despawn-ranges:
      monster:
        hard: 56

• view-distance: 8-10 · simulation-distance: 6-8
• Pre-generate chunks with Chunky before opening to the public
• Monitor with /tps or the Spark plugin

Forge and NeoForge mods

JVM flags

java -Xms4G -Xmx4G \
  -XX:+UseG1GC \
  -XX:+ParallelRefProcEnabled \
  -XX:MaxGCPauseMillis=200 \
  -XX:+DisableExplicitGC \
  -jar paper.jar nogui

Use Java 21 LTS for Minecraft 1.20.5+. G1GC is the default for a 4 GB+ heap. Do not allocate 100% of RAM to Java.

Spark profiler

1. Install Spark (plugin on Paper/Purpur, mod on Forge/NeoForge).
2. Reproduce the lag with an active farm or many players.
3. /spark profiler start → wait 2-5 min → /spark profiler stop.
4. Read the link: plugins, mods or entities at the top are the culprit.

World and entities

• Limit giant automatic farms with staff rules.
• Turn off excessive random_tick_speed if it was changed via gamerule.
• Use WorldBorder to contain infinite exploration.
• Clear-lag plugins or Paper configs for distant items/mobs.
• Scheduled restarts clean plugin memory leaks.

High-clock CPU and NVMe SSD matter as much as config. Minecraft depends on single-core. Measure, change incrementally and take a backup before drastic changes.