Factorio Server Requirements Calculator

RAM

The official headless build is lightweight at startup, often using only 500-700 MB for a fresh or small game. RAM consumption then grows with the size of your explored map, because Factorio keeps every generated chunk loaded in memory and never unloads it. A small co-op vanilla game runs comfortably in 2 GB. A mid-game factory with a handful of players is happy with 4 GB. Large bases, long Space Age playthroughs, or maps with a lot of exploration realistically want 8 GB. True megabases and heavy overhaul mod packs (Bob's & Angel's, Pyanodons, Krastorio) have been observed using 9-13 GB or more, so plan on 16 GB for those. Player count adds very little RAM on its own; budget roughly 100 MB per concurrent player and let map size drive the rest.

CPU

This is the single most important factor and the most misunderstood. Factorio's world simulation runs on one thread (only fluid/pipe calculations are parallelized), so the server's tick rate is capped by the speed of a single core. A modern CPU with high clock speed and strong instructions-per-clock will sustain 60 UPS on a much larger factory than a many-core but slow chip. One or two cores is technically enough to run the game; additional cores only help the operating system and background tasks. When a factory eventually drops below 60 UPS, the cause is almost always single-thread CPU saturation from the sheer number of active entities (inserters, assemblers, trains, biters), not a lack of RAM or cores. Choose the fastest single-core performance you can; do not pay for high core counts expecting them to raise UPS.

Storage

The headless server download itself is small because it ships without graphics assets. A few gigabytes of disk is plenty for the binary plus save files. Typical vanilla saves land around 10-30 MB; large or heavily explored maps grow larger, and extreme modded saves (for example Space Exploration endgame) can approach several hundred megabytes or more. Factorio also writes autosaves on a schedule and keeps several rotated copies, so allow room for multiple save generations. An SSD is strongly recommended: autosaves briefly pause the game while writing, and faster disk I/O keeps that hitch short, especially on large maps. Mods add their own footprint, so add storage if you run a big mod pack.

Bandwidth

Steady-state bandwidth is very modest. Because of the lock-step model, only player input actions cross the network during normal play, often only a few kilobytes per second per client. The exception is the initial map transfer: when a player first joins (or rejoins after desync), the entire save is uploaded to them, which is a brief burst proportional to save-file size. A typical small-to-medium server uses well under a few gigabytes of transfer per player per month. Budget more if you host a large, frequently-joined public server with big saves.

Operating system

The official headless package is 64-bit Linux; Debian and Ubuntu are the most common choices and run fine on a small VPS. The server uses UDP port 34197 by default.

Keep UPS at 60

The goal of every Factorio server is a stable 60 UPS. Since UPS is single-thread bound, the most effective lever is reducing the number of active entities the simulation has to update each tick. Replace burner inserters and small assemblers with fewer, faster, higher-tier machines that do more work per entity. Use beacons and modules to cut machine counts. Bots are cheap when idle but expensive in huge swarms, so keep logistics networks reasonably sized.

Map and biters

Explored chunks stay in memory forever and are simulated for pollution and biter activity. Deleting unused far-flung chunks, and limiting needless exploration, reduces both RAM and CPU load. On peaceful or low-biter settings, the server spends fewer cycles on enemy pathfinding and evolution.

Server settings

Use the headless build so no GPU/graphics work is done. Tune autosave interval and the number of retained autosaves to balance safety against the brief save-write pause; on large maps, longer intervals reduce hitches. Put saves on an SSD. The multiplayer latency setting trades input responsiveness for tolerance of slower connections, so adjust it to match your players' network quality.

When to upgrade

If UPS sits below 60 with the factory idle (no one connected), you are CPU-bound and need a faster single core, not more RAM or players. If the box swaps to disk or the OOM killer triggers, you need more RAM, usually because the map has grown.

Choosing a host for Factorio

Because Factorio is single-thread bound, the most important hosting question is single-core CPU performance, not the advertised core count. Look for a plan running a recent, high-clock CPU and ask which processor generation is used; a plan with two fast cores will hold 60 UPS on a larger factory than one with many slow cores. Treat raw core count as nearly irrelevant for UPS.

Confirm the RAM allocation is dedicated rather than shared or burstable, and that it is enough for your factory's expected endgame size rather than just its current state, since explored map area only grows. SSD or NVMe storage matters: it shortens the brief pause during autosaves and speeds map transfers to joining players. Check that autosave generations fit within any disk quota.

Verify you can run the official headless build and install mods freely, and that the host opens the required UDP port. Look for the ability to upload and download your own save files easily, and to set autosave and server-settings options. Bandwidth needs are low in steady play, but a public server with frequent joins benefits from generous transfer allowances for the initial map uploads.

Finally, prefer a provider that lets you scale CPU and RAM later without rebuilding, since a Factorio world's demands climb steadily over a long campaign. Beware plans that emphasize player slots as the headline metric; for Factorio, factory size and single-thread speed are what actually determine whether the server stays smooth.

CPU note: Factorio's game simulation runs on a single thread, so high single-core clock speed and IPC matter far more than core count. The main tick (UPS) is bound by one fast core; extra cores only help the OS and incidental tasks. Prioritize a modern CPU with strong single-thread performance.

Factorio's resource use is dominated by factory and explored-map size, not player count. Explored chunks stay loaded in memory permanently, so RAM grows as the map expands. CPU load is single-thread bound: a sprawling factory with thousands of active entities will drop below 60 UPS on one core long before you run out of players. Size your server to your factory's endgame, not to the headcount.