Memory, Estimated RAM and what to do when your server runs out of memory

Every plan comes with a set amount of memory (RAM), and that amount is the limit for your whole server. The "Estimated" RAM figures you see for modpacks are a guide based on the pack's mod loader, not a measurement of that pack. This article explains those figures, how to check your server's memory use, and what to do if it runs short.

What "Estimated RAM" means

In the Modpack Installer, packs show an Est. RAM line with a Recommended and a Minimum figure. At checkout, the RAM sentence starts with "Estimated".

• The estimate comes from the pack's mod loader, for example Forge or Fabric. It is not a measurement of that pack, so two packs on the same loader show the same figures.
• It is a recommendation, not a requirement. You can still order a smaller plan, and you can change plan later.
• A large pack with hundreds of mods can need more than the estimate. A small pack can need less.

Check how much memory your server uses

1. Open your server. The Memory tile on the Cockpit page shows current use against your plan's limit.
2. For more detail, open Metrics. The Memory · heap card shows use over time.
3. Open Health to see past problems. A Memory pressure entry means the server spent time close to its limit.

Sitting comfortably under the limit is healthy. Staying right at the limit for long stretches can cause pauses and lag. For lag in general, see Lag and the TPS timeline.

Signs the server is running out of memory

• The console, or a file in the crash-reports folder, mentions java.lang.OutOfMemoryError.
• The server pauses or lags badly when more players join or explore, and the Memory tile is at the limit.
• The server stops on its own with no clear error, often during busy moments.

The panel doesn't yet tell you directly that your server ran out of memory. Check for the signs above, or open a ticket and we will look. Include roughly when it happened and how many players were online.

What you can do

1. Lower View distance and Simulation distance on the Server Properties page, then restart. Both use more memory as they go up.
2. Lower Max players if trouble starts when the server is full.
3. Remove mods you don't need, especially large world-generation mods.
4. Move to a plan with more RAM. On your server's page choose Plan & Billing, open Change plan and pick a bigger plan. The panel confirms with "Reboot to apply": the new RAM takes effect after you restart the server. See Change your plan or storage.

Good to know

• MineXEngine sets Java's memory settings for you from your plan's RAM. There are no startup flags for you to change.
• Player slots are unlimited on every plan, but every player keeps part of the world loaded, so more players means more memory in use.
• Disk space and RAM are separate. Running low on disk is a different problem with its own warnings.