Vault Hunters 3rd Edition is one of the most unique modpacks available. The vault mechanic - procedurally generated dungeons with random loot and modifiers - creates server loads that standard modpack optimization guides don't cover.
Hardware Requirements
Vault Hunters is demanding but more predictable than kitchen-sink packs like ATM10 because the vault instances are temporary.
| Players | Minimum RAM | Recommended RAM | Storage | |---------|-------------|-----------------|---------| | 1-4 | 6GB | 8GB | 15GB | | 4-8 | 8GB | 10GB | 20GB | | 8-15 | 10GB | 12GB | 30GB | | 15+ | 12GB | 16GB | 40GB |
The vault generation itself is the primary load. When multiple players enter vaults simultaneously, the server generates temporary dimensions with custom structures, mobs, and loot tables. Each active vault adds roughly 1-2GB of temporary memory usage.
Specific JVM Arguments for Vault Hunters
-Xms8G -Xmx8G -XX:+UseG1GC -XX:+ParallelRefProcEnabled
-XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions
-XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=40
-XX:G1MaxNewSizePercent=50 -XX:G1HeapRegionSize=16M
-XX:G1ReservePercent=15 -XX:G1HeapWastePercent=5
-XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=20
-XX:G1MixedGCLiveThresholdPercent=90 -XX:SurvivorRatio=32
-XX:MaxTenuringThreshold=1 -Dusing.aikars.flags=https://mcflags.emc.gs
The key difference from standard ATM10 flags: the higher G1NewSizePercent (40 vs 30) and G1HeapRegionSize (16M vs 8M). Vault Hunters creates many large temporary objects during vault generation, and these settings handle that better.
Server Configuration
In server.properties:
view-distance=8
simulation-distance=6
max-tick-time=180000
The extended max-tick-time (3 minutes) is important. Vault generation can cause temporary long ticks, and the default 60-second timeout would crash the server during heavy vault creation.
Vault-Specific Optimization
Limit Simultaneous Vaults
The Vault Hunters mod config lets you control how many vaults can be active at once. For servers with less than 12GB RAM, limit it to 3-4 simultaneous vaults:
In the mod's config file:
max_active_vaults = 4
Each vault is an independently generated dimension. If 8 players all enter vaults at the same time, that's 8 temporary dimensions the server has to manage simultaneously.
Vault Timer and Difficulty
Leave the vault timer at default. Shortening vault timers means players rush and die more, creating repeated vault entries that stress the server. Longer timers mean fewer total vault runs per hour.
Common Issues
Server crashes when entering vaults: Usually insufficient RAM. Vault generation is memory-intensive. If your server uses 90%+ of allocated RAM before vault entry, it will crash during generation. Increase your heap size.
Vault lag spikes: Normal during the first few seconds of vault generation. The temporary dimension is being created. If lag persists throughout the vault, check that your CPU has strong single-thread performance.
Vault loot tables empty: This happens after modpack updates if config files are outdated. Regenerate the vault config files by deleting them and letting the mod recreate defaults.
Why Hosting Matters for Vault Hunters
Vault Hunters is unusually sensitive to CPU performance because vault generation relies entirely on single-thread speed. A host with high core count but low clock speed will struggle with this modpack.
Space-Node's hosting uses the Ryzen 9 7950X3D with 5.7GHz boost clock, which generates vaults faster than any other available processor. Combined with NVMe SSD for instant temporary dimension loading, vault entries feel nearly instant for players.
