Game Run In The "very High" Graphics Settings

so with 12 gigs of ram and a supposedly sick card like the 4890, one would think a game like counter-strike 1.6, which was made 8 or 9 years ago, would run with constant 100 fps. or you would think that a higher end game like empire total war could run in the "very high" graphics settings.

well, my fps CAN be 100...but it drops to 20 to 50 in any combat at all, and ranges from 60 to 100 when basically 'idle'. this is counter-strike 1.6!!! i should be getting 100 fps no problem. and i'm not a nub. vsync is off, i've dled, uninstalled and reinstalled the latest ati drivers and ccc. for empire total war? the gameplay is choppy on ANY setting and i expected better. after removing the sound card and taking the 4890 out of the slot it was in and moving it up a couple slots (i was desperate and tried everything i could!) the empire gameplay seemed to maybe be a bit smoother.