Mac OS X: About Energy Saver Options

Different Energy Saver feature sets are available on different computers. This document describes individual features and their availability.
Opening Energy Saver

Energy Saver is a pane in the System Preferences application. To access it, choose System Preferences from the Apple menu, then choose Energy Saver from the View menu. The features listed below may be turned on or off in the Energy Saver pane.

Energy Saver features

"Wake when the modem detects a ring"

This allows the computer to wake from sleep when the modem detects a ring. You may want to use this feature if you receive faxes regularly but want to allow your computer to sleep in order to conserve energy.

Available on these computers:

"Wake for network administrative access"

Also known as "Wake-on-LAN," this allows network administrators and certain applications to wake the computer from sleep by sending it a special type of network packet.

Available on these computers:

"Restart automatically after a power failure"

This allows your computer to automatically restart after shutting down unexpectedly, usually as the result of a power outage.

Available on these computers:

"Show battery status in menu bar"

This displays information about the battery in the menu bar on portable computers.

Available on these computers:

"Restart automatically after a system 'freeze'"

This is only available to Mac OS X Server. It allows the computer to automatically restart if the operating system stops responding (a "hang" or "freeze").

Available on these computers:

"Reduce processor performance"

Also known as "PowerStep," this option allows the software to change the microprocessor's clock speed and/or turn off the L3 cache, slowing down to conserve power or speeding up when more speed is needed.

Available on these computers:


Note: This feature is not available on PowerBook G4 (Gigabit Ethernet) computers.


About "Deep sleep"

While all PowerBook and iBook computers go into "deep sleep" when Sleep is selected, some older computers do not. Instead, the display turns off and the hard drive spins down, but many other components (including the processor) remain on.

Deep sleep is available on these computers:

Published Date: Oct 10, 2016