Factorio Server Requirements: RAM, CPU and Player Slots Explained
Wube does not publish a dedicated-server RAM chart. Here is how to choose CPU, memory and player slots from factory size, mods and UPS instead of trusting a slot slider.
Factorio aims for 60 updates per second. Each tick has 16.667 ms to finish. If a tick takes longer, the whole factory runs in slow motion for everyone.
Belts, inserters, assemblers, trains, fluids and biters are what fill that time budget. A huge empty-looking slot count on a small map is the wrong way to shop.
A dedicated server does not initialise graphics, so it starts faster and uses less memory than the full game client running the same save.
Wube’s multiplayer FAQ allows for up to 500 players in a single game. In server-settings.json, max_players set to 0 means no limit. That number does not decide how much RAM you need.
What actually uses resources on a Factorio server
Factorio’s multiplayer uses a lockstep design: every instance, including the dedicated server, runs a full simulation of the world and only player actions travel across the network. That is why a quiet four-person megabase can be heavier than a public server with dozens of people wandering a young factory. The machine is replaying the factory, not rendering a lobby.
- No graphics initialised
- Faster startup than a client
- Lower memory use than the full game
The official performance overlay splits that work into named systems. The Update line is the world tick itself, not the picture on anyone’s screen. Inside it, the entity manager is usually the largest cost, because “entities” covers so much of the factory: machines, inserters, biters and a long list of other placed objects. Belts, fluids, heat, circuit networks, electric networks, trains and radar chart updates each have their own lines. If the factory has simply grown past what the CPU can finish in 16.667 ms, no slot upgrade will fix it.
A dedicated server still has an advantage over hosting from a gaming PC. In headless mode, graphics are not initialised. Startup is faster, memory use is lower, and the process runs on a machine that does not need a GPU. The official minimum and recommended PC figures (4 GB RAM and a dual-core 3 GHz+ processor at minimum; 8 GB RAM and a quad-core 3 GHz+ processor recommended) describe the full game client, including a GPU. Treat them as a useful ceiling for a comparable world, not as a dedicated-server shopping list.
Storage matters in a quieter way. The official client minimum includes 3 GB of disk space. The Linux headless package is smaller because it omits graphics and sound, but the live data you care about is the save, the autosaves and the mods folder. Large factories produce larger .zip saves, and the server writes those files during autosaves and on a clean exit. Fast storage shortens those pauses; it does not invent extra UPS if the CPU is already over budget.
UPS: the number that tells you whether the server is coping
UPS means updates per second. It is the game’s internal clock. Factorio always aims for 60 UPS, which is also 60 ticks per second. At 30 UPS, everything takes twice as long: belts, research, trains, biters and crafting. Players feel that as the world running in slow motion, not as a brief graphical stutter.
FPS is different. Frames per second is how often the picture updates on a player’s screen. Low FPS can make the view stutter while the factory itself still runs at full speed. Low UPS slows the simulation for everyone. On a headless server there is no local picture to chase, so UPS is the health metric that matters.
Players can open Factorio’s debug settings with F4 and enable show-fps and show-time-usage while connected. The overlay reports milliseconds per tick, averaged over the last 100 ticks (a little under two seconds). Anything that regularly eats several milliseconds of that 16.667 ms budget is worth a look. The script-update lines show how much individual mods are costing; some mods also raise the cost of core systems, so a cheap-looking script line is not the whole story.
Host panels usually show CPU and RAM graphs rather than UPS. Use both. A CPU graph stuck high while UPS is falling means the world tick no longer fits the time budget. RAM climbing toward the plan limit means the save, the mods and the live simulation are filling memory. Extra unused RAM will not raise UPS on its own once the world already fits comfortably in memory.
Official player figures, and why slots are a poor sizing tool
Hosts often sell Factorio in “30-player” or “100-player” tiers. That packaging is easy to compare at checkout, but it is not how the game decides whether a tick finishes on time.
What Wube actually documents is more useful:
- The official FAQ describes multiplayer as allowing for up to 500 players in a single game.
- The wiki’s hard engine limit is 65,535 players. The practical limit is much lower; popular streamers have managed well over a hundred.
- In
server-settings.json,max_playerscaps how many people can be connected at once. Set it to 0 if you want no limit. - Since version 0.14.8, more than 10 players in one game reduces the rate the game is saved to the server. That is a save-frequency change, not a RAM formula.
Player count is still not free. Each connected person is another character in the simulation and another stream of actions the server has to share. Joining also means downloading the map and catching up. A busy public server with a modest factory can need more network and save patience than a private world of the same size. It is still the factory that usually decides whether you stay at 60 UPS.
Set max_players for the group you actually expect. Raising the cap does not reserve RAM, and a huge allowance on a small plan does not make the factory cheaper to simulate.
How hosts pair RAM with player slots
Because Wube does not publish a dedicated-server RAM chart, the practical figures you will see are the ones hosting companies put on their plans. GTX Gaming, for example, publishes Factorio tiers that always pair a RAM size with a player allowance, while also saying that mods and megabases push RAM long before player count does. Their published pairings are a useful example of how the market packages the same two numbers:
| GTX published RAM | Paired player allowance | What they say it is for |
|---|---|---|
| 2 GB | 30 players | Early factories and small friend groups |
| 3 GB | 40 players | Vanilla worlds through the rocket launch |
| 4 GB | 60 players | Bigger vanilla factories and light mods |
| 6 GB | 80 players | Modded starter packs |
| 8 GB | 100 players | Modded factories and busy community maps |
| 12 GB | 140 players | Large modded communities |
| 16 GB | 180 players | Megabases, Space Exploration and overhauls |
| 32 GB | 320 players | Giant public factories |
GTX’s own guidance on that page matches the engine better than the slot column does: a vanilla world for a small group is comfortable on 2 GB to 3 GB, modded or busier servers should start at 4 GB to 8 GB, and megabases or heavy overhaul mods such as Space Exploration benefit from 16 GB or more. Read those as one host’s published starting points, then judge your own world by UPS and actual memory use rather than by the player number printed next to the plan.
If you are comparing rented servers rather than sizing a home machine, use our best Factorio server hosting shortlist for current plans, locations and regular prices. The wider logic behind CPU, RAM, storage and network choices is in the game server hardware requirements guide.
How to choose RAM, CPU and slots for your factory
Start from the world, not from a slot slider.
A new vanilla factory with friends
A fresh freeplay map and a small group is the lightest common case. The factory is small, the mod list is empty, and headless mode is already saving the graphics overhead a client would pay. Hosts that publish a 2 GB or 3 GB starting tier are aiming at this stage. Give the server a modern CPU with strong per-tick performance, because the world update still has to finish 60 times a second even when the base looks simple.
A growing vanilla world, or Space Age without extra mods
As the factory spreads, entity counts climb and the Update line in the overlay grows with them. Space Age is Wube’s official expansion; it adds more planets and systems to simulate on the same server process. You do not need a separate unofficial RAM rule for it, but you should expect a larger, older Space Age save to need more memory and more CPU time than the same group on a young Nauvis map. If UPS is still 60 and RAM use has room to spare, stay where you are.
Modded factories and overhaul packs
Every player and the server must run exactly the same game version and the same mods. That already makes a modded server stricter to run. Performance-wise, each mod can add a script-update cost and can also make vanilla systems more expensive: more electric networks, more train repathing, more entities. Quality-of-life tweaks are usually lighter than total overhauls. If you are stacking a large pack, start from a host’s higher published RAM tiers and leave headroom, then watch the script-update lines after people have been building for a while.
Megabases and public servers
A megabase, in common Factorio language, is a factory large enough to be measured in science packs per minute, often around 1,000 of each pack per minute. At that point the factory itself is the product. Hosts that publish 16 GB and above for megabases and overhauls are reacting to save size and entity count, not to the idea that 180 people will show up. A public listing can still justify a higher max_players value and more upload, because Wube’s practical examples of very large player counts come from busy streamed games rather than a private evening with friends.
One more dedicated-server setting changes the CPU picture: by default the headless server pauses while nobody is connected. If you override that with no-auto-pause so production, research and biters keep going overnight, the server pays the full world-tick cost around the clock. That is the usual reason a rented Factorio machine needs to hold 60 UPS even at 3 a.m.
How to tell you need more resources
Upgrade when the world tells you to, not when a slot table looks impressive.
| What you notice | What it usually means | What to do |
|---|---|---|
| UPS sits below 60 while people play | A tick is taking more than 16.667 ms. The factory, a heavy mod or both have outgrown the CPU’s time budget. | Read the time-usage overlay. If entity manager or a mod script line dominates, simplify the factory, remove the expensive mod, or move to a faster CPU plan. |
| The factory feels fine until the save is large | Memory use and save time grow with the world. Autosaves and shutdown saves get heavier as the .zip grows. | Check the panel’s RAM graph against your plan size, keep extras in Factorio save backups off the server, and step up RAM if the process is pressing the limit. |
| Only some mods make the overlay spike | That mod’s scripts, or the extra entities it creates, are eating tick time. | Look at the mod-... script-update lines and hidden costs such as trains or electric networks. Remove or replace the offender before buying a bigger plan. |
| Players cannot join after an update | This is a version or mod mismatch, not a RAM shortage. Every instance needs the same game version and the same mods. | Update the server and the players together, and sync the mod list to the save. More RAM will not let a 2.0 client join a different server build. |
| A high player cap on a small factory still feels fine | Expected. Slots are a join limit. A young map has little simulation to do. | Keep the cap at the group you want. Spend money on CPU headroom later, when the factory is the thing that grew. |
Factorio server requirements FAQ
How much RAM does a Factorio server need?
Wube does not publish a dedicated-server RAM figure. The official client minimum is 4 GB and the recommended client figure is 8 GB, and a headless server uses less memory than that full client because it does not initialise graphics. Hosts that publish their own tiers often start small vanilla groups at 2 GB to 3 GB, point modded servers at 4 GB to 8 GB, and reserve 16 GB or more for megabases and heavy overhauls. Size yours by watching actual memory use and UPS on the save you run.
Is CPU or RAM more important for Factorio?
CPU decides whether each world tick finishes inside 16.667 ms, which is what keeps UPS at 60. RAM decides whether the save, the mods and the live simulation fit without pressure. A megabase with falling UPS needs faster world-tick performance; a growing modded save that is climbing through its memory allocation needs more RAM. Extra unused RAM will not raise UPS on its own.
How many players can a Factorio server handle?
The official FAQ allows for up to 500 players in a single game. The wiki’s hard limit is 65,535, with a much lower practical limit; streamers have run well over a hundred. In settings, max_players of 0 means no cap. In practice the factory’s size usually becomes the limit before those official numbers do.
Do mods change Factorio server requirements?
Yes. Players and the server must run the same mods at the same versions, and those mods add script time plus any extra entities or systems they create. A small quality-of-life list is a different load from an overhaul pack. Check the script-update overlay after the factory has been running, rather than assuming a slot tier covers every mod list.
Can I host a Factorio server on a machine that meets the official minimum specs?
The published 4 GB / dual-core 3 GHz+ figures are for the game client, including graphics. A headless server on similar CPU and RAM can run a modest factory because it skips rendering, but a large or heavily modded world can still outgrow that machine. If you host at home, remember the server also needs a stable upload, port 34197/UDP, and a PC that can stay on if you want the factory running while you are away.
More Factorio server guides
Our Factorio host comparison, plus the save and backup guide for moving a world onto the plan you pick.
Written for Factorio’s dedicated headless server in November 2026. Client system requirements and the 500-player multiplayer figure come from Wube’s official FAQ; ports, player limits, lockstep behaviour, headless memory use and the 60 UPS / 16.667 ms tick budget come from the official Factorio Wiki. The RAM and player pairings in the host table are GTX Gaming’s published tier sizes, not an official Wube hardware chart.
