Asmoday

"In my time as being a computer enthusiast (read nerd) I have seen a few trends occur. The move to bigger systems, then the move back to smaller systems and so on. All through these trends though, there has always been one factor that stayed the same. That factor is noise. With the bulk of most people running air-cooling in there computers, noise is bound to be a menace. With better cooling comes faster fans, and with faster fans comes more noise.

Truthfully do you need those fans spinning at full power all the time? A lot of times you probably will not. For example, your processor will not need as much cooling while you surf the Internet as it will as you frag your face off in your favorite game. So controlling your fans at certain times can be very advantageous."

Source : Viperlair