how many face is suggested per object, per project

hi, im using maya for modeling, i remember reading somewhere about the suggested number of face per object, and per scene but i cant recall where it was. anyone ? please help.

The question can't be answered without more details:

What hardware are you targeting? Which platform? How many % of these vertices will be skinned? What kind of shaders are you going to use? How many texture slots? How many different materials?