The Energy Saver preferences pane controls how your Mac responds to inactivity. You can use the Energy Saver preferences pane to put your Mac to sleep, turn off your display, and spin down your hard drives, all to save energy. You can also use the Energy Saver preferences pane to manage your UPS (Uninterruptible Power Supply).
Before making any adjustments to the Energy Saver preferences pane, it’s a good idea to understand just what putting your Mac to sleep means.
Sleep: All Macs
- Your Mac’s processor goes into low-power mode, significantly reducing energy consumption.
- The Mac’s video output is turned off. Any connected display should either enter its own idle state (manufacturer dependent) or at the very least, blank the screen.
- Internal hard drives will spin down. Note: Not all third-party drives support a spin down or sleep state.
Sleep: Mac Portables
- The expansion card slot powers off. Any device that is plugged into the expansion card slot will be disabled.
- If Energy Saver optional settings allow for it, the built-in modem will turn off.
- If Energy Saver optional settings allow for it, the built-in Ethernet port is turned off.
- If Energy Saver optional settings allow for it, built-in AirPort cards are turned off.
- Optical media drive is turned off.
- Audio in and out is disabled.
- Keyboard illumination, if present, is disabled.
- USB ports are powered down, although they will respond to specific keystrokes on an external keyboard.
The process of configuring the Energy Saver preferences pane is the same on all Macs.
Launch the Energy Saver Preferences Pane
- Click the ‘System Preferences’ icon in the Dock or select ‘System Preferences’ from the Apple menu.
- Click the ‘Energy Saver’ icon in the Hardware section of the System Preferences window.