If fans are off below 55 C they are quiet, last longer, and use less energy. It is my understanding that temps below 60C are harmless to CPU's and GPU's so why not leave the fans off at lower temps? I've been fine tuning my fan curves using Argus Monitor and I'm real happy with the results. My computer idles between 30 & 55 C depending on the ambient room temp so the fans will stay off until I play a game or edit photos. Argus Monitor has a hysteresis setting that keeps the fans from throttling.