4870 core clock staying at 500MHz

sir when you are on desktop and not playing games your card downclocks to 500mhz to save energy and running cooler since you dont need the raw power to surf internet. when you will run a game the cards will automatically clock to your desired settings. the same principle applies to processors like what intel has with speedstep.

hi...but what if the clocks don't get back at 750 with 900 mhz when playing ... i tested it with gpu-z the same ... sometimes it works sometimes it doesn't, help pleaseee same gpu 4870