A couple of ways to do this...hit the tilde key (`) to bring down the console and type net_graph 1, 2, or 3. Using net_graph will show you your frames but will at the same time eat up frames as well, if you're gonna use net_graph use number 3 as it uses the least amount of frames...or even better, in console type cl_showfps 1. This won't eat your frames and shows them in the upper left hand corner of the screen in little white numbers
