Hint brushes explain proper use pls

[doomsday2002]

I think we all need a better understanding of hint brushes to lower our fps,can any1 explain this in simple terms(i know it aint simple but...)
for instance,if u got 2 rooms connected by a door where is the correct placement and how should the hint brush be constructed so as you dont draw the other room b4 u enter it?
making things detailed just seems to help the compile process quicker but not fps.
Any knowledgable peeps out there who can help us all?
cheers.

dooms.

[tltrude]

http://www.qeradiant.com/manual/Q3Rad_M ... htm#tools4

[doomsday2002]

cheers.