How To Optimize Your Forge Server Performance

Forge has been one of the most popular modloaders for modpacks for quite some time now. This guide will go over which mods you should install on your server for the best performance on your Forge server.

Tip

Before proceeding with this guide, please follow our general Performance Guide for server optimizations that apply to all Minecraft servers.

Note

This guide assumes that Forge is installed on your server already. Please see the following guide for more info.

Additionally, all the mods listed below will need to be uploaded to the mods folder on your server. For more info on how to install mods please refer to the following guide.

Recommended Mods by Version

Different versions of Forge have vastly different mods available for performance. Select your version below to see our recommended performance mods for your version of Forge.

Please note that if a mod is not listed, it may change vanilla behavior or is generally considered broken by the community.

Forge 1.21.1 and Beyond

This version of Minecraft mainly focused on a handful of exploit patches and technical changes. These mods focus on similar major gameplay logic issues like 1.20.1.

• Radium: Radium is 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

This version of Minecraft contains patches to lighting engine issues from previous versions. These mods focus on other major areas for improvement on your server.

• Radium: Radium is 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.
• 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 of Minecraft still has some of the major issues from 1.18 regarding lighting engine issues and other general logic slow-downs. These mods do an excellent job at addressing those issues on your server.

• Radium: Radium is one of the most important mods for performance on a server. Radium optimizes gameplay logic without changing vanilla mechanics.
• Starlight: Starlight will greatly speed 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 1.18.2

This version of Minecraft introduced new world height and terrain generation changes. These mods attempt to address issues with the new changes.

• Radium: Radium is one of the most important mods for performance on a server. Radium optimizes gameplay logic without changing vanilla mechanics.
• Starlight: Starlight will greatly speed 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 of Minecraft is generally not very performant compared to other versions. These mods attempt to address issues with the most problematic issues on a server.

• Radon: Radon will greatly speed up chunk generation and ticking.
• FerriteCore: Moderate reduction in RAM usage from patches to block states and locations.
• RoadRunner: RoadRunner is one of the most important mods for performance on a Forge server. RoadRunner 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.

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Things to Avoid

To maintain a healthy server, you should avoid the following common pitfalls:

• Paid “Lag Removal” Mods: Most paid performance mods are unnecessary and can introduce gameplay-breaking bugs.
• Item Stackers/Clearers: Modern software like Paper handles item merging efficiently already. Mods that aggressively clear ground items often frustrate players and use more CPU resources than they save.
• Mob Stackers: These can cause more lag by constantly scanning for entities to stack. It is better to limit mob spawn rates in your config than to stack them after they spawn.

It is also highly recommended to pre-generate chunks on your server. Please refer to the following guide for detailed steps on how to do this.

If you have followed this guide and are still experiencing issues, you should analyze your server using the Spark profiler. Check out the following guide from the Spark developers for more information: Spark Guide for instructions on how to track down the specific cause of your lag.

As always, if you get stuck or have any questions, just reach out to a bro on Discord.