Alienware M17x ( mid 2009 ) graphics card lag

I have an alienware m17x, i know its old but it can still run most games smoothly but i  can't play as long, as the laptop become with very hot  and each key can be painful to type. I've played 2 games of counter strike and after closing the game, the laptop suddenyly become very laggy. I've tried draining all the power, my drivers are updated and also restarted my computer several times. On Save Power, It runs more smoothly then Boost performance, is there any way to fix this?