Consider for Photon

A mod that fixes random memory leaks for both the client and server

Improve and tweak Minecraft thread scheduling. Fork of Smooth Boot for ≥1.20

Particle optimizations: Culling, rendering optimizations, configurable particle-type-specific spawn reduction, and potion particle disabling. Compatible with Sodium, improves performance over Sodium alone.

Async particle tick/rendering

Vanilla Worldgen optimization mod

Distribute HUD updates over multiple frames to improve performance. Now supports 1.21.11!

Removes configured rendering layers to increase performance when rendering items, armor, weapons, etc.

A less powerful optimization mod. Performs various optimizations: chunks, culling, opengl, nbt and network.

A port of a mixin mod Nothirium to 1.8.9.