well mine is the 2500k. At 2000 rpm or under I don't consider it loud, even with the case open and it right up on my desk, but then I have no vid card, mech. drives hooked up yet, nor any case fans, and my power supply is fanless, so that's the only noise period. I will say that compared to the stock hyper 212 fan at full speed it is VERY quiet. Anyway I am going to run some tests using handbrake and some gaming and see where my temps fall under "normal" use. I am going to buy a new cooler regardless, but depending on what I find I may be doing it sooner than later. I am not going to let it run 80c plus that's for sure...