Ok, an update, you need to replace the thermal pad with thermal grease... the chips are completely leveled, at least on my machine, 10 degrees difference!!!
Then for silent cooling it's this side that needs it. I chooked the sideways fan so it doesn't blow on the top fans, you could try with a smaller fan that doesn't reach over the top too.
Edit: definetly go for 92mm fan for the side fan.The little black thing on the right ledge is a spider that likes the miner. It lives next to it!
It's not sleep quiet, but it's almost work quiet, not in the same room, but at least it keeps the neighbors from complaining.
Too bad BFL "ran out" of heatpipes!
EDIT: The position of the side fan is dangereous, I suspect it blows directly at the temperature sensor therefore tricking the single it is cooler than it actually is. I burned 1 chip for good and 3 more that needs cooling before booting to work! Damn BFL for not delivering heatpipes so we could cool these quietly!!!The chips are all back, seems the firmware is shutting things down if they get too hot; even across reboots!?