HL2 I can max out and still pull 45 FPS.
L4D I can crank up pretty high in most everything, but I can't max-out the AA; I pull almost a perfect 55 FPS.
TF2 hates me. Whether I have everything at it's lowest, or if it's almost entirely maxed out (can't go above 8x AA), I ALWAYS pull between 20 and 120 FPS.
It just likes to flip from one extreme to another.
Sitting in a spawn-room alone, I'll be pulling framerates my monitor can't actually display.
Walk out into the middle of a map ALONE, in an EMPTY server, and it'll drop to 30, sometimes less.
For those curious, open up your console using your ` key, and type in "net_graph 1" to display some stats, such as your ping and FPS.
"net_graph 2" and "net_graph 3" display more in-depth statistics.
This should work in ALL Source games, as far as I know. I use it in most everything by default
