A modpack server needs two to four times the memory of a vanilla server with the same player count. How much exactly depends on the pack, and the developers are not always clear about it. Below you will find per popular pack what the maker recommends, separated from what we advise for a server with five to ten players.
Per pack: maker recommendation vs our advice
| Modpack | Loader / version | Java | Maker says | Our advice (5 to 10 players) |
|---|---|---|---|---|
| All The Mods 10 | NeoForge 1.21.1 | 21 | No number; "around 500 mods" | 10 to 12 GB |
| All The Mods 11 | NeoForge 26.1.2 | 25 | No number; "super early alpha" | 12 GB or more, expect crashes |
| Cobblemon (official, Fabric) | Fabric 1.21.1 | 21 | "Minimum 2.5 GB, use 3 GB+" (client) | 4 to 6 GB |
| Pixelmon 9.4 | NeoForge 1.21.1 | 21 | No number | 6 to 8 GB |
| Prominence II: Hasturian Era | Fabric 1.20.1 | 17 | No number | 6 to 8 GB |
| RLCraft 2.9.3 | Forge 1.12.2 | 8 | "We recommend 3 to 4 GB" (client) | 4 to 6 GB |
The "Maker says" column comes from the CurseForge pages, checked on 3 September 2026. Where a maker provides a number, it almost always refers to the client, not the server. A server loads the world for everyone simultaneously and therefore needs more than a single client.
How we arrive at our advice
Three factors determine the memory of a modpack server. In order of weight:
- The number of mods. Every mod loads blocks, items and recipes into memory, even if nobody uses them. A pack with 500 mods (All The Mods 10) starts at around 6 to 7 GB before the first player joins. A pack with 100 mods (Cobblemon) starts at around 2 GB.
- Loaded chunks. Players who spread out across the map each load their own section of the world. Ten players scattered across the map cost more than ten players at one base. A lower
view-distance(6 to 8 instead of 10) makes a noticeable difference. - Player count. Budget 300 to 500 MB per player in a heavy pack, 150 to 250 MB in a light one.
Our advice is the base usage of the pack plus ten players, with headroom for peaks when loading new areas. Playing with three friends? Take the lower end. Building large factories with Create or Mekanism? Take the upper end.
More RAM is not always better
Java cleans up memory with a garbage collector. If you give a server 16 GB while it only uses 6 GB, the collector waits longer and then cleans up a larger batch at once. That causes stutters, not improvements. Choose the memory that fits and not the maximum you can afford. If in doubt, start one tier lower and check the actual usage in the game panel. Upgrading is always possible without losing the world.
How to tell the pack does not have enough
Three signals in the console or panel:
- Memory usage in the panel sits consistently above 90 percent of the allocated amount.
- The console shows
java.lang.OutOfMemoryError: Java heap spacejust before a crash. - The server stutters every few seconds, especially when players explore new terrain. That is the garbage collector working overtime.
What to do when you need more
Upgrade your plan in the game panel. HostValues allows you to scale memory without losing your world, plugins or settings. If the pack simply needs more than your current plan offers, the next tier up is a click away.
Check the Minecraft hosting plans to find the right fit for your modpack. Already running into stutters on a modpack server? Our guide on reducing Minecraft server lag covers the tuning side.
Can I run two modpacks on one server?
No. Each modpack requires its own server instance with its own set of mods and configuration. Running two packs on one server is not supported by any mod loader.
Does the Java version matter for memory?
Indirectly. Java 25 (required for Minecraft 26.x) handles memory differently from Java 17 or Java 8. Using the wrong Java version will not just affect memory; the server will refuse to start entirely. Match the Java version to the Minecraft version the modpack targets.
My pack uses more RAM than expected. Is that normal?
Yes, especially right after startup. Mod registrations, recipe loading and initial chunk generation all spike memory usage. Wait until the server has been running for five minutes before judging the baseline. If it stays high after that, you need a larger plan.
