a little known tweak (even for geforce users who use nvrefreshfix) is that HL and each mod folder have a config.cfg file that specifies a maximum refresh rate for the game, default at 72fps. it is called max_fps and it is near the middle-end of the file usually. even with nvrefreshfix on my gf3 i was gettin 72 fps till i made max_fps "150" and i have gotten 99fps constantly.