How to Optimize Your Modded Minecraft Server

Latency is one of the most frustrating issues for any Minecraft server, causing delays when placing blocks or interacting with the world. While general guides exist on types of latency and how to reduce it, they often lack optimizations for modded servers. At HolyHosting, we provide additional guidance to help you optimize your modded server and improve its performance.

Forge Server

The most common type of modded server you might be using is a Forge server. Most one-click modpacks provided by HolyHosting run on Forge. If you’re unsure whether a modpack is running on Forge, you can check on CurseForge. If there’s no mention of Fabric, it’s usually a good sign that it’s not a Fabric modpack and is instead running on Forge.

View Distance

Forge servers don’t offer many built-in settings for optimization. The best configuration you can adjust is the server view distance. The view distance determines how many chunks around each player are loaded.

For example, setting the server view distance to 6 will load a limited number of chunks around each player, reducing server load and improving performance.

By default, each server has a view distance of 10. This may be fine in some cases, but if you’re experiencing lag on your modded server, it’s best to start here and lower this value.

For modded servers, we recommend a view distance of 4–6 to improve performance while still maintaining a reasonable in-game view.

To change the view distance, follow these steps:

• Go to your HolyHosting Panel and log in.

  
  

• Click Config Files on the left side of the panel, then select Server Settings.

  
  

• Locate and change the view distance setting according to your preference.

  
  

• Click Save at the bottom, return to the main panel page, and restart the server for the changes to take effect.

You can calculate how many chunks are loaded around each player using this formula:

(2 × x + 1)²

where x is your current view distance. The lower the number, the better for performance.

Pre-Generating Chunks

A very common cause of lag on modpacks and modded servers is chunk generation. Players want to explore, discover custom biomes, dimensions, and creatures. Constantly exploring and generating new chunks can heavily impact server performance.

This is why pre-generating chunks on the server is an excellent way to improve performance.

The best way to generate chunks in your world is with a mod called Chunk-Pregenerator. This mod should work regardless of your server version and has releases from 1.4.6 up to 1.16.5.

After installing the mod, you can run a simple generation command like:

/pregen start gen radius GenExample SQUARE 0 0 100

This will generate everything within a 100-chunk radius in the dimension you are in, starting at coordinates (0,0) in your world. You can adjust the radius as needed — for example, increase the 100 value to include a much larger generation area.

We encourage you to explore more features on the mod’s CurseForge page.

Server Profiling

If you’ve tried reducing the view distance or pre-generating chunks and are still experiencing lag, there may be something very specific causing issues. This is where server profiling comes in. You can use the built-in Forge debug profiler to identify exact sources of latency.

To run the debug profiler:

• Go to the console in your HolyHosting panel.

• Enter the command:

debug start

Make sure not to include a / at the beginning of the command.

• Let the debug profiler run for 20–30 minutes.

• After the time has passed, enter:

debug stop

You’ve now successfully run the debug profiler. The results will be saved as a text file in a folder called debug within your server’s FTP files.

Here’s an example of what you might find when reviewing your debug results:

The section depth is defined by the number. In this example, we’ll look at line 02. To the right, you’ll see that the name of the specific section is tick.

Next to the name, the first percentage represents the time taken relative to its parent section. For Layer 0, this is the percentage of time per tick, while for Layer 1, it’s the percentage relative to its parent. The second percentage shows the total time spent on the entire tick — in this case, 95.81%.

SpongeForge

Installing SpongeForge on your modded server opens up many opportunities to increase server performance. SpongeForge is available for modded servers running Minecraft versions 1.10.2 through 1.12.2.

The first important feature SpongeForge offers is timings reports.

These reports help you identify the biggest stressors on your server. This is similar to the debug profiling mentioned earlier but provides more detailed insights. You can generate a timings report with the following commands:

• In-game, enter:

/sponge timings on

• Wait approximately 20–30 minutes, then enter:

/sponge timings paste

After running the paste command, a link will be generated where you can view the report. Here’s an example of what a report might look like:

In this case, the large orange section indicates a significant TPS loss on the server. Looking closer, one of the main causes was chunk generation, which accounted for 58% of the tick.

Sponge Plugins

Installing SpongeForge is excellent for advanced server profiling, but you can also add many performance-enhancing plugins alongside it. Here are some recommended plugins:

• CatClearLag: A Sponge remake of the famous ClearLagg plugin. It can periodically clear entities/items on the ground.

  
  

• Mobpression: Compresses mobs to help reduce entity counts, useful for mob farms on your server.

  
  

• EpicBanItem: Allows you to ban crafting or using specific items, helpful for certain mods that may cause significant lag.

  
  

Forge Mods

Not all servers can run SpongeForge due to version compatibility. If you’re running very old or very new Forge versions, SpongeForge may not be an option. Fortunately, there are plenty of performance-enhancing mods you can add:

• AI Improvements (1.7.10–1.16.5): Optimizes entity AI to improve server performance.

  
  

• RandomPatches (1.8.9–1.16.5): A configurable collection of bug fixes and quality-of-life improvements, including tweakable hard-coded settings.

  
  

• FoamFix (1.7.10–1.14.4): Universal optimization mod that reduces Java memory usage through various patches.

  
  

• Performant (1.12.2–1.16.5): Lightweight mod improving entity AI, login times, entity collisions, and more.

  
  

• Surge (1.10.2/1.12.2): Open-source mod aimed at improving game load times and overall performance.

  
  

• Spark (1.12.2/1.15.2–1.16.5): Forge version of the popular Sponge plugin Spark; used for advanced server profiling to pinpoint specific sources of lag.

  
  

Fabric Server

Fabric is another type of modded server you might be running. While it is designed to be lighter and more modular, it can still experience lag under certain circumstances.

Like Forge, Fabric lacks built-in configuration options to improve performance. The best configuration recommendation is to reduce the server’s view distance, similar to Forge servers. This will decrease the number of chunks loaded in the world.

The main solution for lag on Fabric servers is to add performance-enhancing mods and profile the server to identify what might be causing in-game issues. Below is a list of recommended mods for your Fabric server:

Fabric Mods

There are many excellent performance-enhancing mods for Fabric. Here are some we recommend to optimize your server and reduce potential lag:

• Lithium (1.15.2–1.16.5): A general-purpose optimization mod for Minecraft that improves various systems (game physics, mob AI, block ticking, etc.) without altering gameplay behavior.

  
  

• Phosphor (1.15.2–1.16.5): Optimizes Minecraft’s lighting engine, which can significantly reduce dimension load times.

  
  

• Spark (1.15.2–1.16.5): The Fabric version of the popular Sponge plugin Spark, used for profiling server performance and pinpointing specific sources of lag.

  
  

• Fat Experience Orbs (1.14–1.16.5): Merges all experience orbs into a single orb. Extremely useful for large XP farms, this mod can drastically reduce lag in affected areas.

Conclusion

We hope this guide has been helpful! 🚀 Remember, don’t hesitate to ask questions on the HolyHosting Discord or contact our support team.

Follow us on Twitter @HolyHosting to stay up to date.

Stuffy @ HolyHosting