Aikar Flags

Aikar Flags are currently the most optimised and tested startup flags for Minecraft. As such they’re are recommended for newer versions of the game, modded servers, and public servers.

Applying The Flags - Game Servers

If you're using our game panel, you can set these flags on your server overview page. Our panel will set the flags for you, so you don't need to follow any of the steps on this page.

Applying The Flags - VPS

If you have our game panel installed on your VPS, then you can use the quick toggle on the server overview page. If you don't, then you'll need to manually set your flags.

Correct Flags To Use

If your server is using under 13gb of RAM, then these are the flags you should use.

java -Xms12G -Xmx12G -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1 -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:InitiatingHeapOccupancyPercent=15 -Dusing.aikars.flags=https://mcflags.emc.gs (opens in a new tab) -Daikars.new.flags=true -jar server.jar nogui

Note: Change the RAM value to the amount of RAM your server has

If you’re using 13gb of RAM or more, then some changes are needed.

java -Xms13G -Xmx13G -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1 -XX:G1NewSizePercent=40 -XX:G1MaxNewSizePercent=50 -XX:G1HeapRegionSize=16M -XX:G1ReservePercent=15 -XX:InitiatingHeapOccupancyPercent=20 -Dusing.aikars.flags=https://mcflags.emc.gs (opens in a new tab) -Daikars.new.flags=true -jar server.jar nogui

Note: Change the RAM value to the amount of RAM your server has

How Much RAM Should I Give

First, don’t give all your systems memory. These startup settings will use all the memory provided. So if you have a 14gb system, and give all 14gb, you don’t leave any memory for other processes on that system.

This also applies to anyone using the pterodactyl panel.

When setting the ram value, it’s a good idea to set it 1gb under your systems RAM

More Isn’t Better

It’s common for people to think that giving more RAM to your server will solve all your problems. However this ofter can at best not solve any issues, and at worse, make the server crash more frequently.