This mod optimizes npcs, rendering, and other players.
It adds a setting to the settings menu titled, 'use effects.' setting this to "don't use effects" may drastically improve performance.
The configuration option "cull distance" determines how far away from the camera a player / prop needs to be to get culled. When an object is culled, it will move at a much lower framerate. When a player is culled, animations will temporarily pause.