How to Optimize Your Forge Server Performance

Forge has been one of the most popular mod loaders for modpacks for years. This guide covers the best performance mods for each Forge version to help reduce lag and improve server responsiveness.

💡 Tip: Before installing these mods, make sure you've followed our general Performance Guide for server optimizations that apply to all Minecraft servers.

📝 Note: This guide assumes Forge is already installed on your server. If not, see our version guide to switch to Forge. To upload mods, follow our mod installation guide.

Recommended Mods by Version

Different Forge versions have vastly different mods available. Find your version below for our recommended performance mods.

Mods not listed here either change vanilla behavior or are generally considered unstable by the community.

Forge 1.21.1 and Beyond

• Radium: One of the most important mods for performance on a server. Radium optimizes gameplay logic without changing vanilla mechanics.
• FerriteCore: Moderate reduction in RAM usage from patches to block states and locations.
• ModernFix: Fixes various bugs and improves startup time and memory footprint.
• Structure Layout Optimizer: Improves generation speed of structures, especially with larger modded structures.
• Krypton: Networking and packet delivery optimization.

Forge 1.20.1

• Radium: Optimizes gameplay logic without changing vanilla mechanics.
• FerriteCore: Moderate reduction in RAM usage from patches to block states and locations.
• ModernFix: Fixes various bugs and improves startup time.
• Structure Layout Optimizer: Improves generation speed of structures, especially with larger modded structures.
• Krypton: Networking and packet delivery optimization.
• Alternate Current: Optimizes redstone dust by reducing unneeded calculations.

Forge 1.19.2

This version still has lighting engine issues from 1.18. These mods address the most impactful performance problems.

• Radium: Optimizes gameplay logic without changing vanilla mechanics.
• Starlight: Greatly speeds up chunk generation and ticking by rewriting the lighting engine.
• FerriteCore: Moderate reduction in RAM usage from patches to block states and locations.
• ModernFix: Fixes various bugs and improves startup time.
• Structure Layout Optimizer: Improves generation speed of structures, especially with larger modded structures.
• Krypton: Networking and packet delivery optimization.
• Alternate Current: Optimizes redstone dust by reducing unneeded calculations.

Forge 1.18.2

This version introduced new world height and terrain generation, creating new performance challenges.

• Radium: Optimizes gameplay logic without changing vanilla mechanics.
• Starlight: Greatly speeds up chunk generation and ticking.
• FerriteCore: Moderate reduction in RAM usage from patches to block states and locations.
• ModernFix: Fixes various bugs and improves startup time.
• Structure Layout Optimizer: Improves generation speed of structures, especially with larger modded structures.
• Krypton: Networking and packet delivery optimization.
• Alternate Current: Optimizes redstone dust by reducing unneeded calculations.

Forge 1.16.5

This version is generally less performant than newer releases. These mods address the biggest bottlenecks.

• Radon: Greatly speeds up chunk generation and ticking.
• FerriteCore: Moderate reduction in RAM usage from patches to block states and locations.
• RoadRunner: One of the most important mods for performance on a Forge server. Optimizes gameplay logic without changing vanilla mechanics.
• ModernFix: Fixes various bugs and improves startup time.
• Structure Layout Optimizer: Improves generation speed of structures, especially with larger modded structures.
• AI Improvements: Reduces CPU overhead of some entity logic.

Next Steps

It is highly recommended to pre-generate chunks on your server. This eliminates terrain generation lag during gameplay.

If you've followed this guide and are still experiencing issues, analyze your server using the Spark profiler. Check out the Spark Guide for instructions on tracking down the specific cause of your lag.

As always, if you get stuck or have any questions, just join our Discord.