How much RAM does an SMP server need? From 5 friends to 40 players
The question we get most often from groups starting an SMP: how much RAM should I get? The honest answer is that the number of players matters far less than people think. A Paper server with ten friends building quietly runs fine on 5 GB, while four players tearing across a fresh world on elytras can make an 8 GB server stutter. Below are the rules of thumb we use, where they come from and what you should configure before you even think about more memory.
The rule of thumb by number of players
| Players online at once | RAM | At MC-Node | Suits |
|---|---|---|---|
| 1 to 10 | 5 GB | Redstone, €5.50 p/m | Vanilla or Paper, a handful of plugins, view distance 8 |
| 10 to 20 | 8 GB | Dirt, €8.80 p/m | Paper with voice chat, a map and CoreProtect |
| 20 to 25 | 10 GB | Clay, €11.00 p/m | Lots of plugins, Bedrock players via Geyser |
| 25 to 40 | 15 GB | Gravel, €15.00 p/m | Community server, big world, map rendering |
These figures assume Paper on the latest version and a view distance of 8. They match the player guidance on our Minecraft packages, which cost about €1.10 per GB. Modpacks follow different rules; those are in How much RAM does your modpack server need?.
Where the memory really goes
A Minecraft server uses memory mainly for loaded chunks. Every player keeps a square of chunks around them in memory, and you decide how big that is with view-distance and simulation-distance. Ten players living close together share chunks and cost little between them; ten players each exploring a different side of the world load ten times as much. That's why the number of players is a rough measure and the way people play is the real one.
- View distance 8 instead of 10 saves about a third of the loaded chunks. For an SMP, 8 is plenty; 6 already feels cramped.
- Simulation distance 6 determines how far away mobs and crops are active. Lower than 5 breaks farms; higher than 8 costs a lot of CPU and memory.
- Generating new chunks is the heaviest thing a server does. With a world border and Chunky you generate everything in advance, after which the server only has to load instead of calculate.
What plugins cost
Most plugins cost next to nothing: Simple Voice Chat, LuckPerms, a revive plugin and DiscordSRV together account for a few hundred megabytes. Two exceptions:
- CoreProtect writes to a database that can grow to gigabytes on disk, but uses little RAM. Set the retention period to a few weeks.
- BlueMap and Dynmap use serious CPU and memory while rendering new areas. Render the world once at a quiet moment; after that the upkeep is light.
An overview of which plugins an SMP really needs is in The best plugins for a hardcore SMP.
Bedrock players and big groups
Geyser translates every Bedrock packet to Java and back. That costs some extra CPU and memory per Bedrock player; count on roughly double a Java player. So five extra friends on phone or console is no problem on 8 GB, but twenty Bedrock players call for 10 GB or more. How to set that up is in Java and Bedrock together on one server.
More RAM isn't always better
This is the trap: Java divides up the allocated memory and cleans it up periodically. Give a ten-player server 16 GB and Java will happily fill it, and every clean-up round takes longer, with small stutters as a result. Our panel starts Minecraft with the usual Aikar flags that temper that behaviour, but the principle stands: pick the smallest size that fits and upgrade when the numbers say so. Upgrading is one click and loses no data.
How to measure whether you have enough
- Look at the memory usage in your panel during a busy evening. If you're consistently above 85 percent, one size up is sensible.
- Check the TPS with
/tps. If it stays at 20 while players report lag, the problem is their connection or the view distance, not the memory. - Install spark and see what's eating the time. It's often one plugin or one farm, not the amount of RAM. The guide is in fixing lag with spark and in TPS, MSPT and lag: what the numbers really mean.
A hardcore SMP: any different from regular survival?
No. Hardcore changes the difficulty and what happens after death, not the load on the server. What you do see more often with hardcore groups is players building far apart, because nobody wants a creeper next to someone else's base. That means more loaded chunks per player, so for a hardcore season with fifteen players round up to 8 GB rather than 5 GB.
Quick decision guide
Torn between two sizes? Decide based on three questions. How many players are online at the same time on a busy evening, not how many are on the whitelist? Do they play close together or spread across the world? And are you running a map or Bedrock players? Two answers of "a lot" means one size up. A group of eight friends building a village together and going on the occasional adventure has plenty of room with 5 GB; the same group with BlueMap, voice chat and four cousins on the Nintendo Switch is a typical 8 GB case. And because upgrading is one click, starting too small is never an expensive mistake.