In the G73 series, the fans are placed in the back and do an excellent job of displacing the heat generated by the cpu and gpu. Overheating hasn't been my issue, the hd 5870 has just died on me several times since I have owned this laptop. I haven't attempted to overclock and my computer never lags right when I get it back from RMA, but after a while it starts to stutter and then goes downhill from there until i hit BSODs.