mine makes a high pitched whistle constantly, not even when its reading or writing
Ditto. I've handled a total of 7 disks (RAPTORS) from different lots and they all go "WHOOOO WHOOOO!!!".
Kind of annoying, but that's the nature of the beast! The newest 15k drives are far quieter by comparison. It's kind of pathetic actually.
As far as the quietest HD, you know EVERY SINGLE drive out there is dead SILENT when powered off!
I have a Cuda V (80GB w/two platters) and can hear it spin up. Idle is VERY quiet. (ear needs to be NEXT to the drive to hear anything and that's just a peep!) Out of the box, seeks were nearly muted however they were 18 mS! Disabling drive acoustic control brought them down to the normal 13 mS range but made them audible. Not annoyingly so. Seeks never really bothered me anyways. (for the exception of the "marbles in the blender sound" of the original cheetah and "bombs in baghdad" rumble of the crappy 40MB MFM drives by Seagate our government purchased back in '91.)
-DAK-