iMac System Preferences: The Energy Saver Pane
If you’re an environmentalist (it’s surprising how many techno-types are green) and an iMac user, the Energy Saver pane of your iMac’s System Preferences (as shown in the following figure) is pretty doggone important.
When you use them correctly, you not only save electricity but also even invoke the Power of Mavericks to automatically start and shut down your iMac whenever you like!
To save electricity, drag the Computer Sleep slider to a delay period that triggers sleep mode when you’re away from the keyboard for a significant period of time. (Consider 30 minutes.) If your iMac must always remain alert and you want to disable sleep mode entirely, choose Never. You can set the delay period for blanking your monitor separately from the sleep setting with the Display Sleep slider.
To conserve the maximum juice and cut down on wear, select the Put Hard Disks to Sleep When Possible check box to power-down your hard drives when they’re not needed. (This might cause a delay of a second or two while loading or saving files because the drives must spin back up — if you’re sharing files with others on your network, sleeping hard drives can also significantly slow file transfers.)
You can set Mavericks to start or shut down your iMac at a scheduled time. Click the Schedule button and then select the desired schedules (the Start Up or Wake check box and the Shut Down/Restart/Sleep pop-up menu) to enable them. Set the trigger time by clicking the up and down arrows next to the time display for each schedule. Click OK to return to the Energy Saver pane.
Select the Wake for Network Access check box to wake your iMac from sleep mode whenever your computer is accessed remotely across your network. Mavericks can restart your iMac automatically after a power failure — a good feature for those running their iMac as a server, because your server will automatically come back online after power is restored.