just add another 2gb of ram and see how it goes..if the games still lag it may be an overheating issue with either the cpu or gpu..or it could even be your psu..maybe its not being able to provide enough amps during critical parts of gameplay and thus leading to slowdowns ? have you faced any crashes while playing ?
no mohit. no crashes while playing !! just lags . and not that much lags but like slight,. frame rates drop n all