# Forge Minecraft Server Performance Guide (/docs/minecraft/forge-optimize)



Forge servers are heavier than vanilla or Paper. Here's how to keep performance acceptable.

Performance Mods for Forge [#performance-mods-for-forge]

| Mod                                                  | Purpose                                  |
| ---------------------------------------------------- | ---------------------------------------- |
| [Spark](https://modrinth.com/mod/spark)              | Profiler — find what's causing lag       |
| [FerriteCore](https://modrinth.com/mod/ferrite-core) | Reduce RAM usage                         |
| [Clumps](https://modrinth.com/mod/clumps)            | Groups XP orbs to reduce entity count    |
| [Fastload](https://modrinth.com/mod/fastload)        | Faster world loading                     |
| [Chunky](https://modrinth.com/mod/chunky)            | Pre-generate chunks to eliminate gen lag |

Configuration Tips [#configuration-tips]

server.properties [#serverproperties]

```properties
view-distance=8
simulation-distance=6
max-tick-time=-1
```

JVM Flags [#jvm-flags]

Apply [Aikar's JVM flags](/docs/minecraft/jvm-flags) — they help Forge servers significantly.

RAM Allocation [#ram-allocation]

Forge modded servers need more RAM:

* Small modpack (50 mods): 4–6 GB
* Medium modpack (100 mods): 6–8 GB
* Large modpack (200+ mods): 8–12 GB

> ⚠️ **Don't over-allocate** — giving 16GB when you need 6GB makes GC pauses worse.

Identifying Lag Sources [#identifying-lag-sources]

Install Spark and run:

```
/spark profiler start
```

Wait 5 minutes, then:

```
/spark profiler stop
```

The generated report shows exactly which mods/tasks consume the most tick time.

Related Guides [#related-guides]

* [Install Mods](/docs/minecraft/mod-setup)
* [Performance Guide](/docs/minecraft/optimize-server)
* [JVM Flags](/docs/minecraft/jvm-flags)