in Idlebetrieb constant room temperature (about 22 ° C) under full load with Prime95 under 50 ° C and even up to 100% turns the fan is pleasantly quiet, of course, he can be heard, but even if you minimize all other background noise in the room)
The only thing I have to say (and this is not a criticism but just a note) - check your measurements in the housing, the heat sink is really big, I unpack really get scared: D
Anyway - Very strong buy recommendation, thanks to Amazon and Thermalright.