Vault Hunters 3 Server RAM: How Much You Need

Published November 2, 2026

Short answer: 10 GB for a small group (2 to 5 players), 12 GB for 6 to 10, and more beyond that. 8 GB is the floor: it boots, but it has little headroom once several players are in vaults at the same time. Below 8 GB, don't bother.

Vault Hunters 3rd Edition (VH3) is a Forge pack on Minecraft 1.18.2. The pack's CurseForge page lists 3.21.7 as the latest release (July 2026) with a separate server-files download, but it gives no server RAM figure. Its only memory advice is for players: set the launcher's allocated memory to 8192 MB. Server numbers online come from hosts, and they range from 8 GB to 16 GB. Here's how we size it and why.

RAM by group size

The 8 and 10 GB rows match what most hosts and the pack's own client setting say. The bigger rows are our estimate, using the rule of thumb in our modpack RAM guide: about 1 GB more for every few extra players, plus extra for VH3 because each open vault is its own world. Our order page sets the minimum for Vault Hunters at 8 GB and recommends 10 GB.

Why Vault Hunters needs more than a normal pack

• Every vault is a fresh dimension. When a player starts a vault, the server generates and loads a new area for it. Three friends running three separate vaults means three extra areas in memory at once, on top of the overworld.
• Generation is CPU work on one thread. Building a vault happens on the main server thread. If that thread is busy, everyone feels it as a lag spike when someone enters a vault. Extra RAM doesn't speed this up.
• Big bases with storage and machines. Late game VH3 bases run storage systems and machines that tick all the time.

So size RAM for the number of vaults that will be open at once, then watch CPU.

First boot takes a while

In our own provisioning check, Vault Hunters on an 8 GB plan took about 12 minutes (735 seconds) from order to the server answering a status ping. That was one check, not a benchmark, but expect the first start to be slow and don't restart it halfway through.

Fixing lag on a Vault Hunters server

1. Check memory first. If the console shows OutOfMemoryError or the server crashes when someone enters a vault, it needs more RAM. Go up a size.
2. If memory is fine, profile. Use spark (it has Forge builds for 1.18.2, if your server doesn't have it already): run /spark tps, then /spark profiler start, play for a few minutes, and /spark profiler stop. The report shows which mod or block uses the time.
3. Pre-generate the overworld. Chunky has a Forge 1.18.2 build (1.2.164). It's server-side only, so players don't need it. Run /chunky radius 2000 then /chunky start while nobody is on. Vaults still generate live, but the overworld won't.
4. Stagger vault runs on a small plan. Two or three players running vaults together is easier on the server than five starting at once.

The same "RAM or CPU?" check, for an older and heavier pack, is in our RLCraft server lag fixes.

Java version

VH3 runs on Minecraft 1.18.2 with Forge 40.x, which runs on Java 17. Don't use Java 8, and stick to 17 rather than a newer Java. On Packyard the right Java is set for you; running it yourself, see which Java version a Minecraft server needs.

What it costs on Packyard

Packyard charges $1.50 per GB of RAM per month (USD plus applicable taxes), so 8 GB is $12, 10 GB is $15 and 12 GB is $18. The order page shows which sizes are in stock right now. The pack installs in one click, the server stays on, it has a permanent address (yourserver.play.packyard.ca), and it includes daily backups plus backups you make yourself in the panel, SFTP, and sub-users for friends who help run it. Available in the US and Canada (not Quebec); servers run in US West.

Run Vault Hunters 3 on Packyard, from $12. Comparing packs first? See modded Minecraft server hosting or try the RAM calculator.

Vault Hunters is made by its authors. Packyard is not affiliated with Vault Hunters, Mojang or Microsoft.

FAQ

Can Vault Hunters run on 6 GB?

Not reliably. It may boot, but vault entry and a few players will push it out of memory. Our order page won't sell it below 8 GB.

Is 16 GB too much for Vault Hunters?

For 2 to 5 players, yes. Past about 12 GB, extra RAM brings little; lag at that point is CPU, not memory.

Why does my server lag when someone enters a vault?

The server builds the vault on its main thread, so there's a short spike for everyone. If it's a crash rather than a spike, it's usually memory: go up a size.

Which Vault Hunters version does a Packyard server run?

As of November 2026, new servers install the 3.21.7 server files (Forge 40.3.11, Minecraft 1.18.2). Everyone who joins needs the same pack version in their launcher.

Do my friends need to install anything?

Yes, the Vault Hunters 3rd Edition modpack in the CurseForge launcher, on the same version as the server. Then they join with your server's address.

More guides and posts on the Packyard blog.