I have a new dell l502x with i7 and 540m with 6 gb of ram and 1080p display but I have gotten lag on many games such as mw2 cod4 and kerbal space program but it only works properly when I am using my power cable is there any way i can fix this and it is not normal lag it goes from 60 - 70 fps down to 6 - 20. anyone got any solutions. I have tried disabling step speed, battery power settings and nvidia control panel updating all grphics software and nothing has worked!