I'm fighting that silence vs airflow vs cooling battle at the moment. Yes, I know I shouldn't really be talking about "silence" when I'm running a 9SG1212P1G01, but since it is loud-ish I intend to drop the noise elsewhere. Proved with a horrible noisy clattering Delta 120x38 @ 7V that good top exhaust helps my case really well.
After checking out ehume's thread:
http://www.overclock.net/t/724577/the-well-dressed-megahalems-65-fans-and-112-setups-56k-warning/20#post_9232257
I've started thinking of the following 3 candidates:
9G1212H1011
9S1212L401
9S1212H401
I'm thinking target voltage of 5V, maybe 7V on the L401.
Can anyone say whether these click at those voltages? Do they hum or have motor noise that would exceed their airflow noise?