I have the 2U. You just cannot hear the 2U fan. I always hear the Fractal, which is quiet too, but the 2U is DEAD quiet. You'll be looking for the fan to see if it's actually working. Matt from Fractal has a video where he "mikes" the 1U and you can hear how "loud" it is (it's not that loud of course, but it is not dead quiet as the 2U).