Check your current Java version (Java 8/17/21 depending on your Minecraft version)
Close Minecraft and any launchers you don’t need
Open your Minecraft launcher
Go to Installations (or Settings → Installations)
Select the Minecraft instance you want to change
Find “More Options” (or “Advanced”)
Locate the JVM arguments field
Edit the JVM arguments to set RAM, using:
`-Xms4G -Xmx8G`
Example (increase to 12GB total):
`-Xms4G -Xmx12G`
Apply/Save changes
Launch Minecraft using that same installation/profile
For multiple mods, increase RAM gradually (e.g., 6G → 8G → 10G) if the game stutters or crashes
Ensure you have enough free system RAM to avoid swapping
If using a mod launcher (e.g., CurseForge/FTB), open its instance settings and adjust the “Memory” or “RAM” slider
If using a server, set the server JVM args (e.g., `-Xms4G -Xmx8G`) in the startup script or command
If Minecraft still doesn’t use the new RAM, verify you edited the correct installation/profile and that the launcher didn’t overwrite the JVM arguments