Im building a new PC, (athlon 64 X2 4200+ GF 7800 GT blah blah) Right now the only fan I have for external air is a 120mm fan to mount on the rear of the case. I might add an 80mm to the side mount in the future. My question is, is it better to mount the fan so it blows air into the case or so it blows air out of the case? Im pretty uneducated when it comes to cooling so any info you might have would be helpful, thanks.