Portalium

Portalium is a performance mod that helps modpacks specifically by unloading dimensions no one is in. It works by monitoring which dimensions have players in them and unloads those that don't. When the last player leaves a dimension a short timer starts counting down before the dimension is now dormant, meaning its chunks are unloaded from memory and it's removed from the server's tick loop, saving CPU and RAM and even giving more TPS.  This mod is compatible with most other mods like Mekanism, Ice and Fire, Lycanites Mobs, etc. and custom dimensions for your convenience.

If you come across any errors, PLEASE leave a brief comment explaining the error to help me update it and help out other users, thank you!