I own a sager np8130 (I think) or a clevo p151hm1 laptop, when ordered we had it custom built with an upgraded i7 2670qm 2.2-3.1ghz as well as 8gb of ram and a gtx 560m gpu, wonderful laptop, very capable, but im power hungry, I can get my hands on a 580m for a decent price, and those things rip, if I purchase the gtx 580m installation wont be a problem but will I need a new heatsink/fan and will the 180w psu cover it (currently using 120w adapter)