i have the HR-02 + Thermalight TY-140 fan using pwm. the fan spins at 500-600rpm idle and no more than 800rpm at full load, it can go faster but my temps(load 55C) don't get high enough to push it. my case is an Fractal R4 using only the two stock fans running at 7v. My pc is: 3770k 8GB of Corsair Low Profile(large ram heatsinks might hit the fan on a hr-02) Asus gtx 670 120mm fan PSU Samsung 830 SSD 2TB Western Digital Red for storage in terms of noise if i set the case fans to 5v i cant hear the pc at all unless the storage drive spins up or i put my ear right against the case. this is at night when there's little to no ambient noise pollution. i build with as quiet as possible in mind. i wasnt sure how the HR-02 would work out but i'm more than impressed. I highly recommend the thermalright fan as well, top notch stuff.