Calamity Mod Server Hosting: What You Actually Need

Calamity turns Terraria into a different game. Over 25 new bosses, hundreds of items, new biomes, new progression systems - it’s essentially a DLC built as a mod. Your server setup should account for that.

This isn’t about convincing you to play Calamity. If you’re here, you’ve already decided. This is about making multiplayer actually work: how much RAM you need, which companion mods are worth adding, and what to do when things break.

How Much RAM for a Calamity Server

You’ll find wildly different numbers online. Some guides say 2GB is fine, others recommend 8GB+. The confusion comes from one simple fact: nobody runs just Calamity. By the time you add the QoL mods that make the experience bearable - Boss Checklist, Recipe Browser, Magic Storage - you’re already past the baseline estimates.

Here’s what we recommend:

Why 6GB as the baseline? Client-side memory data from tModLoader logs shows a typical Calamity + Infernum + QoL stack runs around 3.7GB. That’s before accounting for world data, multiple players, and the entity spam that happens during Providence or Supreme Calamitas. 6GB gives you headroom to not worry about it.

At $1.99/GB, the difference between 4GB and 6GB is $4/month. That’s worth avoiding a mid-playthrough “server keeps crashing during boss fights” upgrade.

The 4-5GB tier can work - we’re not saying it won’t. But you’re operating near the ceiling, and Calamity’s endgame is where things get demanding. If you’re on a tight budget and playing with 2-3 people, start there and upgrade when needed. You can bump your plan mid-billing cycle without losing your world.

Companion Mods Worth Adding

Calamity is great on its own, but a few additions make the experience significantly better.

The Essentials

These are lightweight and solve real problems:

Boss Checklist - Calamity has over 25 bosses with specific progression requirements. You need this to track what’s next and what you’ve missed.

Recipe Browser - Hundreds of new items means complex crafting trees. This mod lets you search recipes instead of tabbing to the wiki constantly.

Magic Storage - Your chest situation will spiral out of control otherwise. Calamity drops a lot of materials.

Calamity Music - This one’s client-side only, so it doesn’t run on your server. But everyone should install it locally. The soundtrack is half the experience.

Add-ons That Increase Requirements

Infernum Mode reworks boss AI for players who want a harder challenge. In our testing, it increased RAM usage by roughly 0.5-1GB.

Catalyst adds superbosses and endgame content beyond Supreme Calamitas. Similar overhead to Infernum - plan for around 500MB additional.

CalValEX (Calamity’s Vanities) adds pets and cosmetics. Minimal server impact - this one’s mostly visual.

Stacking Content Mods

Calamity + Thorium is a popular combination, but it’s ambitious. Both mods add full progression systems, new biomes, and lots of entities. We see players hit 4GB ceilings regularly with this combo.

For first modded playthroughs, one major content mod plus QoL additions usually hits the sweet spot. If you’re set on running both, budget 8GB+ and generate a Large world to fit everything.

Common Problems and Fixes

Server Crashes on Join or “Out of Memory”

This usually means the server is hitting its RAM ceiling during mod loading or world generation. The most common cause we see on other hosts: 32-bit tModLoader caps at 4GB regardless of what plan you’re paying for.

If you’re crashing despite having enough RAM on paper, check whether your host runs 64-bit tModLoader. WinterNode runs 64-bit by default, so this ceiling isn’t something you’ll hit with us. But if you’re comparing notes with friends on other hosts or troubleshooting a self-hosted setup, that’s often the culprit.

Mods Disappearing from enabled.json

This one’s frustrating. You configure your mod list, restart the server, and half your mods are gone.

Here’s what’s happening: tModLoader automatically disables mods that error on startup. It also clears the console when loading finishes, so the error messages disappear. You’re left with no mods and no explanation.

On WinterNode, the winternode.log file in the root of your file manager preserves console output from startup - including the errors that tModLoader clears. Check there first.

General fix: make sure mod versions match exactly across all players. Even minor version differences can cause load failures. Enable mods one at a time to isolate which one’s causing problems.

Lag Spikes During Boss Fights

Calamity’s endgame bosses - Providence, Devourer of Gods, Supreme Calamitas - spawn massive projectile counts. If you’re seeing lag only during intense fights that recovers afterward, in most cases, this is CPU or simulation load rather than RAM.

More memory helps only if you’re actually memory-constrained. What helps: making sure your host doesn’t throttle CPU during load spikes. Some budget hosts cap CPU usage to keep costs down, which makes bullet-hell bosses unplayable.

”Mod Version Mismatch” When Players Join

Everyone needs identical mod versions. Even minor updates break compatibility.

The fix: create a Steam Workshop collection with your exact mod list and share the link with players. One click subscribes to everything and keeps versions synced. On the server side, double-check that enabled.json matches what players have installed.

World Doesn’t Have Calamity Biomes

Content mods generate their biomes and structures at world creation, not retroactively. If you installed Calamity after creating the world, the Sulphurous Sea, Brimstone Crags, and Abyss won’t be there.

Fix: generate a fresh world with your full mod stack enabled before creation.

Quick Setup Tips

Use Medium or Large Worlds

Small worlds don’t generate Calamity biomes properly. The official Calamity wiki explicitly says small worlds aren’t supported - there’s not enough space for all the new biomes and structures.

Large is ideal. Medium is playable. Small will break things.

Generating enabled.json the Easy Way

Manually typing every mod name with correct syntax is tedious and error-prone. Here’s the shortcut:

Set up tModLoader locally on your PC. Enable only the mods you want on your server. Then copy your local enabled.json file (found in Documents/My Games/Terraria/tModLoader/Mods/) directly to your server’s Mods folder.

This ensures mod names match exactly and skips the typo debugging.

Test Locally First

Load your mod combination in singleplayer on your PC before uploading to the server. If it crashes locally, it’ll crash on the server. This catches mod conflicts before you’re doing server-side troubleshooting.

Getting Started

When ordering a Terraria server, select tModLoader as your server software. If you started with vanilla and want to switch, open a support ticket and we’ll handle the conversion.

For step-by-step mod installation, we have a guide in our help center that covers the process.

If you run into issues - crashes, mods not loading, performance problems - our support team can help via ticket or Discord. We’ll look at your logs with you rather than just suggesting you upgrade to a bigger plan.

We’re obviously biased, but WinterNode exists because we wanted hosting that didn’t nickel-and-dime people. All our game servers are $1.99/GB - a 6GB Calamity setup runs $11.94/month. We don’t charge extra for CPU usage, storage, or basic features that other hosts mark up.

Everything’s backed by our 48-hour refund policy, so there’s no risk in trying things out.

Got questions? Our support team responds to tickets with actual humans, and we’re active on Discord if you prefer real-time help.