Power, Temperature and Noise
Remember this is system-wide power consumption evaluated at the mains. Sapphire's card can, quite comfortably, be powered by a sub-500W PSU.
Excellent under-load temperatures usually mean one of two things: impressive engineering or an overly-aggressive fan-speed profile.
Sapphire's twin fan spin at approximately 1,450rpm when idling. This rises to 2,600rpm after five minutes load, leading to clearly audible noise. We'd recommend Sapphire reduce the focus on temperature, by up to 10 degrees, for a quieter overall noise profile.
