Things in Framerate and Profile

I know what physics, logic, rasterizer, sound, and outside are, but what is scenegraph, services, and overhead? I’ve been using Blender for a long time not knowing what these things are. And combined, they usually take up 10-20% of the processing. I just want to know because I was wondering if I could do something involving one of these to improve the framerate.

scenegraph is the object management engine (controls thir position scale and orientation) you can reduce that number using less objects

services and overhead depends gratly on the environment, if saturn is alingned with neptune, and the color of ton’s underwear