Trying to find the difference between these options, and how they work together. I know that the "Put the Hard Disk to Sleep When Possible" option sets the disks to spin down after 10 mins of use. However, if I enable "Computer Sleep" and set it to 30 mins, while leaving the "Put the Hard Disks to Sleep" option unchecked, will the "Computer Sleep" function still spin the disks down? According to Apple, the sleep mode... What happens when the Mac goes to sleep (not just into idle mode or display sleep)? On all Macs: The microprocessor goes into a low-power mode Video output is turned off, and a connected display may turn off as well, or enter its own idle state Apple-supplied hard disks spin down; third-party hard disks may spin down But if that option is left unchecked, will the disks spin down, or no? I'm guessing they still will, but it's kind of confusing since that option is available.