How to Optimize Your Modded Minecraft Server

Lag is one of the most annoying problems for any Minecraft server, causing delays when placing blocks or interacting with the world. While there are general guides on lag types and how to reduce it, they often lack optimizations for modded servers. At Holy Hosting, we offer additional information to help you optimize your modded server and improve its performance.

Forge Server

The most common type of modded server you might be running would be a Forge server. Most of the one-click modpacks provided by Holy Hosting will run on Forge. If you are not sure whether the modpack is running on Forge, you can look it up on CurseForge. If you do not see any mention of fabric, it is generally a good sign that it is not a fabric modpack but rather running on Forge.

View Distance

Forge servers will not have many settings that can be used to optimize them. The best thing you can do in terms of settings is to reduce the server's view distance. The view distance is used to determine how many chunks around each player will be loaded. Below is an example of the number of chunks loaded around a player with a server view distance of 6.

Each server has a default view distance of 10. This may be fine in some cases, but if you are experiencing lag on your modded server, it is best to start here and reduce this value. We would recommend a view distance of 4-6 for modded servers, to increase performance while maintaining an adequate view distance for gameplay. To change the view distance, follow these steps:

• Go to your Holy Hosting Panel and log in.
  
  
• Click on Config Files on the left side of the panel and then select Server Settings.
  
  
• Find and change the view distance setting according to your preferences.
  
  
• Finally, you will need to click Save at the bottom and then return to the main panel page and restart the server for it to take effect.

You can calculate how many chunks are loaded around each player with this formula: (2x+1)², where x is your current view distance. The lower the number, the better.

Chunk Pre-Generation

A very common cause of lag in modpacks and modded servers is chunk generation. Players will want to explore, find custom biomes, dimensions, and creatures. Constantly exploring and generating new chunks can have a significant impact on server performance. That 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. Regardless of the server version, this mod should work. It has versions from 1.4.6 to 1.16.5. After installing this 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 (0,0) in your world. This can be adjusted to your needs, such as increasing the value of 100 to include many more generation areas.

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

Server Profiling

If you have tried reducing the view distance or generating chunks and still experience lag, something very specific might be causing the issue. This is where server profiling comes in. You can use Forge's built-in debug profiler to find specific sources of lag.

To run the debug profiler, you can do the following:

• Go to your Holy Hosting panel console.
  
  
• Enter the command: debug start (make sure not to use / in the command).
  
  
• Allow the debug profiler to run for about 20-30 minutes.
  
  
• After giving it time to run, issue the command: debug stop.

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

Here is an example of what you might find when checking your debug results:

The section depth is defined as the number. In this example, we will look at line 02. On the right, we see that the specific section name is called tick. To the right of the name, we see the first percentage. This first percentage of 99.31% would be the time it took relative to its parent. For Layer 0, it is the percentage of time a tick takes, while for Layer 1, it is the percentage of time its parent takes. The second percentage of 95.81% is the time it took across the entire tick.

Spongeforge

Installing Spongeforge on your modded server will open many opportunities to increase server performance. Spongeforge is available for modded servers from versions 1.10.2 to 1.12.2.

The first important feature that Spongeforge will offer is timings reports.

This will help you determine what the biggest stressors on your server are. This is similar to the debug profiling mentioned above, but will provide more detailed information. You can run a timings report with the following commands:

• In-game, issue the command `/sponge timings on`.
  
  
• Wait approximately 20-30 minutes and then issue the command `/sponge timings paste`.

After running the paste command, a link will be generated for you to view the report. Below is an example of what a report might look like.

In this case, the large orange section shows a significant TPS loss on the server. If we look more closely, we can see that one of the biggest causes was

chunk generation, which took up 58% of the tick.

Sponge Plugins

Installing Spongeforge is great for advanced server profiling; however, you can also install many performance-enhancing plugins alongside it. Here is a list of recommended plugins you may want to use:

• CatClearLag: This is a Sponge recreation of the famous ClearLagg plugin. It can be used to periodically clean up entities/items on the ground.
  
  
• Mobpression: This plugin is used to compress creatures to help reduce the entity count. This is useful if you have creature farms on your server.
  
  
• EpicBanItem: With this plugin, you can ban the crafting or use of items. This is useful for certain mods that may have items causing a lot of lag on a server.

Forge Mods

Not all servers will be able to run Spongeforge due to version compatibility. If you are running very old or very new versions of Forge, you may not be able to run Spongeforge. Fortunately, there are many performance-enhancing mod options you can add to your server.

• AI Improvements 1.7.10-1.16.5: This mod focuses on improving the AI performance of creatures on your server.
  
  
• RandomPatches 1.8.9-1.16.5: RandomPatches aims to be a highly configurable collection of bug fixes and quality of life improvements for Minecraft, and also allows configuring various hardcoded settings.
  
  
• FoamFix 1.7.10-1.14.4: FoamFix is a universal optimization mod that helps reduce Java memory usage through numerous patches and fixes.
  
  
• Performant 1.12.2-1.16.5: This mod is lightweight and can be used to improve entity AI, login times, entity collisions, and much more.

• Surge 1.10.2/1.12.2: Surge is an open-source mod that aims to improve loading time and game performance.

• Spark 1.12.2/1.15.2-1.16.5: This is a Forge version of the famous Sponge Spark plugin.

It can be used to profile server performance in a more advanced way than typical debugging to help find specific causes of lag.

Fabric Server

Fabric is another type of modded server you may be running. Although it is designed to be more lightweight and modular, it can also experience lag under the right circumstances.

Just like Forge, Fabric lacks settings that can be changed to improve performance. The best thing we can recommend in terms of settings is to reduce your view distance similarly to Forge servers. This will reduce the loaded chunks in the world in the same way. The main solution for lag on Fabric servers will be adding performance-enhancing mods, as well as profiling the server to understand what might be causing issues in the game. Below is a list of mods we recommend for your Fabric server.

Fabric Mods

There are many excellent options for fabric mods that improve performance. Below is a list of recommended mods you can add if you need to further optimize your server and reduce any lag you may be facing.

• Lithium 1.15.2-1.16.5: Lithium is a general-purpose optimization mod for Minecraft that works to improve various systems (game physics, creature AI, block ticking, etc.) without changing any behavior.
  
  
• Phosphor 1.15.2-1.16.5: Phosphor is a Minecraft mod that works to optimize the game's lighting engine. This can drastically decrease loading times for specific dimensions in the game.
  
  
• Spark 1.15.2-1.16.5: This is a Fabric version of the famous Sponge Spark plugin. It can be used to profile server performance and find specific causes of server lag.
  
  
• Fat Experience Orbs 1.14-1.16.5: This mod will merge all experience orbs into a single orb. This is extremely useful if you have built large experience farms. This will help reduce lag in the area significantly.

Conclusion

We hope this guide has been useful to you and remember🚀, don't hesitate to ask on HolyHosting Discord or contact our support.

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Cheers!

Stuffy @ HolyHosting