if you check the option that says "put hard disk to sleep when possible" in energy saver will your hard drive sleep if you are backing up with time machine and don't touch your laptop for a couple of hours with the screen open?
if you check the option that says "put hard disk to sleep when possible" in energy saver will your hard drive sleep if you are backing up with time machine and don't touch your laptop for a couple of hours with the screen open?
If Time Machine needs to sync, then your HD will spin up because it is needed. As soon as the sync is done (and you are still not doing anything), the HD will spin back down.