I am ordering iMac 27 with SSD. Now there's an option to have both SSD and HDD. I am concerned about the noise coming form 2nd, regular HDD. Not only drive itself emits sound. It also contributes to overall temperature and makes iMac fans work harder. Anyone used this setup? I assume we have OSX on SSD and boot form SSD. Does regular HDD spin down when not used? If yes, is there a pause every time you open File open/save dialog and it waits for the drive to wake up? How noisy is that 2nd drive in general? I suppose noisier than whole iMac? Thanks.