Energy Saving Settings

Energy saving modes can go by many different names, including Stand By (Microsoft Windows 95-XP), Sleep (Mac OS-X)/ (Windows Vista), and Suspend (Linux). When placed in this energy saving mode, aside from the RAM which is required to restore the machine's state, the computer attempts to cut power to all unneeded parts of the machine. Because of the large power savings, most laptops automatically enter this mode when the computer is running on batteries and the lid is closed.

 

The following are recommended power management settings:

  • Monitor/display sleep: Turn off after 15 minutes or less
  • Turn off hard drives/hard disk sleep: 15 minutes or less
  • System standby/sleep: After 30 minutes or less (check with your system administrator, if you have one)

 

Energy Saving Modes

Windows 2000/XP

Windows Vista

Mac OS X

Hibernation

Screen Savers

Windows 2000/XP

  1. Select Start > Settings > Control Panel from the Start Menu.
    XP Control Panel

  2. Double-click the Display icon in the Control Panel window.

    XP Display icon

  3. In the Display Properties window, click the Screen Saver tab, then click the Power button in the Energy saving features of monitor box.

    XP Screen Saver Power

  4. Under Power Schemes, select Home/Office Desk.

    XP Power Schemes

  5. Set Turn off monitor for 15 minutes (or less). Set Turn off hard disks for 15 minutes (or less). Set System standby for 30 minutes (or less). Click OK.
  6. To set Password Protect, set the Screen Saver (step 4) to activate at the same time as the monitor turns off (step 5) and check the Password Protected box.

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Windows Vista

  1. Right click on your desktop.
  2. Choose Personalize from the pop-up menu.
  3. Click Change power settings at the bottom of the window.
  4. Click Choose when the computer sleeps from the left column.
  5. Click on Choose when to turn off the display.
    • Many users will be fine with the default configuration.
    • Set your display to turn off sometime between 10 - 20 min after inactivity depending upon your needs.
    • Set Put the computer to sleep to 30 min or a time that best meets your needs.
    • To set password protect, set Screen Saver to activate at the same time as the monitor turns off and check the box for On resume, display logon screen.

Mac OS X

  1. Select the Apple menu.
  2. Select System Preferences...
  3. Select Energy Saver under the Hardware section.
  4. Set Put the computer to sleep when it is inactive to 30 minutes (or less) using the slider.
  5. Check the box for Use separate time to put the display to sleep and set the time to 15 minutes (or less) using the slider.
  6. Check the box for Put the hard disk to sleep when possible.

    Mac System Prefs Energy Saver

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Hibernation

Hibernation is a state in which your computer shuts down to save power but first saves everything in memory on your hard disk. When you restart the computer, your desktop is restored exactly as you left it. Use hibernation to save power when you will be away from the computer for an extended time while working. Hibernation is a way of saving the current state of the computer to disk and is an alternative to powering down the computer. The computer will effectively shut off.  When powered on it will return to the same state at which it was hibernated.as everything is off and RAM just written to disk. 

When your computer is not in use, turn off the power by shutting down or hibernating your desktop.

Hibernation Settings

Mac OS

Sleep is enabled by default or can be chosen via the Apple menu when needed. Safe sleep can be found in newer Macs after October of 2005.  This behaves like the hibernation process but only writes contents to disk so that in the event of a power failure or drained battery the machine can recover.  By default the computer will not power down.

To get your Mac to power down and hibernate you may want to consider using Deep Sleep available at: http://deepsleep.free.fr/.

Windows

To enable hibernation on your machine, go to the Control Panel -> Power Options. Select the Hibernate tab. Check Enable hibernation. Click OK.

The Hibernate feature will then be available when you choose Turn Off Computer from the Start Menu.


Screen Savers

Screen savers are not designed to be energy savers. Their original intent was to protect older CRT displays form having images permanently burned into them. This is not a concern with modern LCD displays. To use password protected energy saving settings on your computer, set the screen saver time to be the same as the monitor turning off.

Screen savers have the potential to consume just as much power as when the display is actively used. These screen saver programs also involve system interaction with your CPU that results in additional power consumption. A blank screen saver is slightly better but even that only reduces display power consumption by a few percent.

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