What is the Entity Culling mod?
Entity Culling is a performance mod for Minecraft: Java Edition, created by tr7zw. It
works out which entities and block entities are hidden from your view and skips rendering them.
Vanilla Minecraft already avoids drawing chunks you cannot see, but individual mobs, item frames, chests
and signs behind a wall can still go through the rendering process. Entity Culling adds a visibility check
for these objects. The check runs on a separate thread, so the main game loop does not wait for it.
Nothing changes on the server side. Mobs keep moving, farms keep running, and other players see exactly
what they saw before. The only difference is what your own client spends time drawing.