Using the timdemo as BFG10K suggested is the best way to tell your average frame rate during different parts of the map and different situations. To do a timerefresh, just type timerefresh in the console though it really is a bad way to check your frame rate. "cg_drawfps 1" in the consoles shows your fps in the upper right hand corner and is constantly changing so it is a bit better than timerefresh though timedemo is still the best way.