Does more RAM mean less lag?

Not on its own. Once the server has enough RAM, lag usually comes from CPU single core speed, view distance, or a heavy plugin or mod.

How much RAM for a modpack server?

Large modpacks often need 6 to 10 GB or more. Check the modpack page, since some list a recommended server memory figure.

How Much RAM Does a Minecraft Server Need?

RAM is the setting people reach for first when a server lags, and it is the one they most often get wrong. This guide shows how much memory a Minecraft server actually needs and what to do when adding more does not help.

RAM is not the only thing that matters#

Memory holds your loaded world, plugins or mods, and player data. Once the server has enough, giving it more does very little. Many lag problems come from CPU single core speed, a high view distance, or one heavy plugin, not a shortage of RAM. Keep that in mind as you size your server.

Recommended RAM by server type#

These are practical starting points. Adjust up if you run a large view distance or many plugins.

Server type	Players	Suggested RAM
Vanilla or Paper, small	1 to 10	2 to 4 GB
Paper with plugins	10 to 30	4 to 6 GB
Large plugin network	30 to 80	8 to 12 GB
Light modpack	1 to 10	4 to 6 GB
Heavy modpack	5 to 20	8 to 12 GB or more

Modpacks are the memory hungry case. Always check the modpack page, since many list a recommended server memory figure.

Set memory with Xms and Xmx#

You allocate memory with two Java flags. -Xms is the starting heap and -Xmx is the maximum. Setting them to the same value is common for servers:

java -Xms6G -Xmx6G -jar server.jar nogui

Never assign all of the machine's RAM to Minecraft. The operating system and Java itself need headroom. On a machine with 8 GB total, giving the server 6 GB is sensible.

Do not over allocate#

It sounds odd, but handing the server too much RAM can hurt. Larger heaps make Java's garbage collector pause for longer, which shows up as periodic stutter. For most servers, right sizing beats maxing out. If you use 6 GB comfortably, jumping to 16 GB rarely helps and can make pauses worse without tuned flags.

Garbage collection flags#

Aikar's flags are a well known set of JVM options that tune garbage collection for Minecraft. They smooth out the pauses that large heaps can cause. Good hosts apply tuned flags for you automatically per server type, so you do not have to memorize them.

How to tell if RAM is really your problem#

Before buying more memory, check the cause:

Watch memory use over time. If it climbs and never drops, you may have a leak in a plugin or mod.
Use a timings or profiler report on Paper to see what eats tick time. Often it is mob farms, redstone, or chunk loading, not memory.
Lower view-distance and simulation-distance a step and measure again. This frees both CPU and RAM.

If your server crashes with an out of memory error, work through our guide on fixing out of memory errors before simply adding more.

Get a sized plan in seconds#

If you would rather not guess, the Prism Nodes RAM calculator recommends a plan from your player count and server type. It takes the math out of picking memory. Use code IMSWITCHING for 15% off your first month.