If the new 2011 iMac is equiped with SSD and HDD at the same time, is HDD running (so fan on) even at times when HDD not used for a longer period?
Context: I need the computer to be really silent (bedroom), and only when exceptionally accessing e.g. video files to use HDD. So if HDD would run all the time, I would rather go for an option of sole SSD in iMac and external HDD which can be unplugged. Otherwise I would go for both in iMac.
Best Answer
Definitely make the SSD your boot/app disk and set your computer to put hard disks to sleep. But even then there are many factors that can cause the drive to spin up even. Sometimes just getting an open dial box will cause it to spin up.
I'd first make sure your HDD is not shown in the sidebar - if it is there it will definitely spin up every time you get a save or open dialog box or a finder window.
Even after doing that I still had it spinning up more than I wanted so I followed this blog post on Dae’s blog to make an apple script that will unmount or mount it so I can explicitly control when it sleeps or doesn't sleep. Incase the link dies, here is the script. It even does Growl notification:
One thing to note - this unmounts ("ejects") an entire drive - not just a single partition.