HINT brushes effectively segments what the engine draws usually if you have a room coming off a corridor or a corridor goes around a corner (

wow that's easy for me too say!).. you should use hint brushes to block it off at the bend... as the engine (from the current players eyes) isn't yet seen......... however, VIS reduction is minimal from a HINT point of view. However FPS will benefit greatly... also on big maps even though you don't need fog make fog (see my scr for that!) make the farplane 10000 (or just play with it) again the engine will not draw past the visible fog distanace helping with FPS.
I turned every brush into detail, with the following exceptions..
SKYBOX (NEVER make detail!!! BUT make the bottom brush CAULK!!)
MODELS
FUNCTION_x (i.e. rotating doors/ladders/windows)
ANY FACE (facet) not seen by a play make CAULK!)
You can make clip brushes detail and hint brushes too....
Don't just put a big hint halfway over your entire map, as this will not work... it will make matters worse.
Another tip... reduce the number of brushes used.... where ever possible.
If you want send me your .map and I'll optimise it for you.
<img border="0" src="file:///C:/Documents%20and%20Settings/Joey/My%20Documents/Image1.gif" width="334" height="219">
If you saw the flash from my gun.. I probably missed!!! But then I seldom do....