Start at 12 GB. Pick 8 GB only for a small map, and only if you are happy with a daily restart. That is the short answer. The longer one is worth five minutes, because the one official figure everybody quotes does not tell you what actually moves the number, and we can show you a week of real readings from our own Rust servers — which, as far as we can find, nobody else publishes.
Facepunch's figure, and what it leaves out
Facepunch's dedicated server requirements say 12 GB of free RAM, with one qualifier: a 6,000 map will use more. That is the whole guidance. There is no table of memory by map size, nothing on population, and nothing on how the number changes over a day of uptime.
It is a fair number for a machine you are setting up yourself. It is less useful when you are choosing a RAM size on a slider, because the question you are really asking is “what does my server need, with my map and my players?” — and the honest answer is that the map decides most of it.
What our servers actually use
We can read the meters. Here is a week of memory readings, taken on 4 September 2026 from the two Rust servers running on our infrastructure — one in Johannesburg, one in Germany. Both have 50 player slots. Both restart once a day.
| Server | Map | Players over the week | Memory after a restart | Memory by the end of the day |
|---|---|---|---|---|
| PvE, vanilla | Procedural, 4,000 | 0 to about 22 | about 8 GB | 10 to 10.5 GB |
| Modded (NPCs, skill tree, backpacks) | Custom map | 0 to 2 | about 8.5 GB | about 10.5 GB |
Two things in that table matter more than the numbers themselves.
The second server was empty all week and used the same memory as the first. Nobody was on it for days at a time, and it still sat at 8.5 GB after every restart and climbed to 10.5 GB before the next one. The first server had up to twenty-odd people on it across evening peaks and read almost identically. Population moved the CPU line on the graph; it barely moved the memory line.
Memory grows through the day and drops at the restart. On both servers the graph is a sawtooth: a restart, a slow climb of two to two and a half gigabytes over the following day, then the next restart. That climb is the server accumulating world state — entities, dropped items, decay timers, everything the map has to remember — and it does not come back down on its own. The restart is what resets it.
One more reading worth having: the 4,000 map was force-wiped during the week, and the fresh map came back at roughly 7 GB with nine players already on it. So a freshly wiped 4,000 map starts around 7 GB and a day later it is at 10.
So what decides the number
In order of how much they matter on the servers we run:
- Map size and map type. This is the floor. A 4,000 procedural map and a typical custom map both start near 8 GB with nobody on. Facepunch's own note that 6,000 maps use more is the same effect at the top of the range. Smaller maps start lower.
- Hours since the last restart. Add two to two and a half gigabytes to the floor for a full day of uptime on a 4,000 map. Restart more often and the peak is lower; run for days without a restart and it keeps climbing.
- Plugins. The modded server above, running NPCs, a skill tree and backpacks, sat about half a gigabyte above the vanilla one at every point in the day. A long plugin list, or plugins that spawn a lot of entities, costs more than that.
- Players. Last, and by a distance. Twenty players versus none was not visible in the memory line on a 4,000 map. Where population does count is at a hundred or more, and in what those players build — a busy server accumulates world state faster, which is the second item on this list, not a per-player cost.
Reading that against the slider
Our Rust slider starts at 8 GB and the order page suggests 12. Here is how the readings map onto that.
- 8 GB is a small-map setting. On a 4,000 map the process is already at 8 GB after a restart and would be against the ceiling within hours. It is a genuine working configuration for a 2,000 or 3,000 map with a daily restart and no heavy plugins, and we list it because some people want exactly that.
- 12 GB is the setting for the server most people actually run: a 3,500 to 4,500 map or a custom map, a normal plugin list, restarted daily. The week above peaks at 10.5 GB, which leaves a gigabyte and a half of headroom at the end of the day. This is also Facepunch's figure, which is not a coincidence.
- 16 GB and up is for larger maps, servers that run for days between restarts, heavy plugin sets, or populations in the hundreds. Facepunch's “6k map will use more” lives here.
How to tell when you have outgrown it
- The server drops or restarts on its own late in the day, and is fine again for a few hours afterwards. That is memory climbing into its ceiling before the scheduled restart gets there.
- The Memory line on your Graphs/History tab flattens against the top instead of climbing steadily. A healthy server climbs and resets; one that has hit its allocation goes flat.
- It got worse after you changed the map size or added plugins, with the same population. That is the floor moving up, not the players.
What is not a memory problem: rubber-banding for one player while everyone else is fine (their connection), or a long load when joining a big map for the first time (normal).
The one thing that is free: a daily restart
Both servers above restart once a day and that is what keeps the peak at 10.5 GB rather than higher. Set it under Scheduled Tasks in the game panel, at your quietest hour. It costs nothing and it is the single most effective thing on this page.
Changing your RAM later
RAM is not a decision you are locked into. Your map, saves and player data live in your server's identity folder, not in the memory allocation, so you can move the slider up or down from your account as the server grows or shrinks, and the world comes with you. You pay for whatever you set, which is the reason not to over-buy at the start: begin at 12, watch the graph for a week, and move it if the graph tells you to.
What we are not going to give you
A megabytes-per-player figure. On the servers we run it would be close to zero on a normal map, which is true and also useless, because the thing that actually costs memory is the map and how long it has been running. What we can give you is a real week of readings, the order in which things matter, and where each slider setting genuinely fits.
If you are not sure what your server needs, open a ticket and we will look at the graph with you.
See also: what a Rust dedicated server actually needs · wipe day and scheduling your own wipes · installing Oxide and plugins · settings, server.cfg and RCON.
