Core Keeper Server Requirements Calculator

Core Keeper dedicated server requirements

Core Keeper ships a free official dedicated server as a Steam tool (App ID 1963720), installable through the Steam client under Tools or via SteamCMD. It runs on Windows 10/11 64-bit and Linux (Ubuntu 18.04+), and the community Docker image will even start on ARM hardware like a Raspberry Pi 3/4/5. That tells you something important: this is not a resource-hungry server. For most groups the limiting factor is CPU clock speed and how far the world has been explored, not raw RAM.

RAM

A fresh server for one to four players runs comfortably in about 2 GB of RAM. Once you go past four players, or your world has been heavily explored and built up, plan on 3-4 GB. The dedicated server caps a session at roughly 8-10 players, so there is little reason to provision beyond 4 GB for vanilla play. Memory use grows mainly with the size of the loaded/explored map and the number of active entities (enemies, dropped items, conveyor and automation setups), not linearly with players. If you run mods, budget roughly 1.5x the vanilla figure, around 6 GB for a busy modded world.

CPU

The minimum is a dual-core AMD or Intel CPU at 2.4 GHz or higher. The key nuance is that the simulation is heavily single-thread-bound, so a couple of fast modern cores will outperform many slow ones. Two cores are fine for a small co-op group; three to four fast cores give comfortable headroom for a full 8-10 player server, a large mapped world, or mods. If you see rubber-banding or rising tick latency as players spread out, it is almost always per-core CPU performance, not a RAM shortage.

Storage

The server install itself is small, and a single world save is only tens of megabytes. Allow about 5 GB of total storage to cover the install, the OS overhead, multiple world saves and rolling backups. World files grow slowly as more of the map is explored, but even an extensively mapped world stays modest, so storage is rarely a constraint. SSD storage is preferable for faster world loads but is not required.

Network and bandwidth

Core Keeper uses UDP and typically needs ports 27015 and 27016 opened/forwarded (the exact ports are configurable). Bandwidth per player is light compared with shooters, on the order of a few GB per active player per month, so budget roughly 8 GB per player monthly as a safe ceiling for normal play. A wired, low-latency connection matters more than raw throughput; a central dedicated server also gives everyone fairer ping than hosting from one player's home machine.

Operating system

Both 64-bit Windows 10/11 and modern Linux distributions are supported. Linux is the common choice for always-on hosting because it is lightweight and scripts/Docker make updates and restarts easy to automate.

Optimizing a Core Keeper server

Because the server is so light on hardware, most performance problems come from configuration and uptime rather than under-spec'd hardware. A few practical steps keep it smooth:

• Restart on a schedule. Long-running sessions can develop memory creep and degraded tick performance over time. A daily or every-few-days automatic restart clears this out and is the single most effective fix players report.
• Match MaxPlayers to your hardware. Set the player cap in ServerConfig.json to what your CPU can actually sustain. Lowering it is the quickest cure for rubber-banding on a small box.
• Prioritize CPU clock speed. If you can choose hardware, a host with high single-core performance beats one with more but slower cores. The simulation leans on a small number of threads.
• Keep the server off the play machine. Hosting and playing on the same PC competes for the same cores and causes lag, especially with mods or large worlds. A separate box or rented instance avoids this.
• Back up world saves regularly. Saves are tiny, so frequent backups cost almost nothing and protect against corruption.
• Be conservative with mods. Each mod adds entities and memory overhead; add them one at a time and watch RAM and tick rate.

Update the server promptly after game patches, since clients usually must match the server version to connect.

What to look for in a host

Core Keeper's modest requirements mean you have a wide range of viable options, so judge a host on fit and reliability rather than raw size. Useful things to check:

• Per-core CPU speed. Ask about clock speed and CPU generation, not just core count. The simulation favors a few fast cores, so a modern high-clock chip serves Core Keeper better than many older, slower ones.
• Right-sized RAM with room to grow. 2-4 GB covers vanilla play; make sure you can bump up easily if you add mods or your world grows.
• Full config access. You want to edit ServerConfig.json (player cap, world settings, ports) and ideally use SteamCMD or a Docker workflow for updates.
• UDP port control. Confirm you can open or forward the required UDP ports.
• Automated backups and restarts. Built-in scheduled restarts and world backups directly address the two most common issues, memory creep and save loss.
• Low-latency, central location. Pick a data-center region near the bulk of your players for fair ping, and look for solid uptime and DDoS protection.
• SSD storage and easy version updates. Faster world loads and a simple way to stay on the current game version.

Self-hosting on a spare PC, mini-PC or even a Raspberry Pi is entirely realistic for small groups; a rented instance mainly buys you uptime, a central location and convenience.

CPU note: Core Keeper's server is single-thread-heavy: a few fast modern cores (2.4 GHz+) matter far more than many slow ones. 2 cores handle a small group; 3-4 fast cores give headroom for the 8-10 player cap, large explored worlds and mods. Per-core clock speed is the real bottleneck.

Figures are conservative estimates for the official Core Keeper Dedicated Server tool (Steam App ID 1963720). The server is genuinely lightweight, it even runs on a Raspberry Pi 4, so RAM is rarely the limit; long-explored worlds and high player counts are. The game itself caps a session around 8-10 players, so there is no benefit to sizing past 4 GB unless you run mods or very large worlds.