I recently decided to upgrade my old gateway gt5670 pc.
I installed a coolermaster extreme 500w psu and an Evga 9800gt.
It works fine I havent seen any problems atm
when I play cod4, the gameplay is smooth and gpu usage is average at 90%
but when I play a mmo game which requires lower reqs,
I get a low gps and only a gpu usage average an 5%. The fps I get ingame is between 10 to 25. It drops to 5 when I walk to crowded areas.
Sorry if made any typos, typing this on an itouch.