PowerBook, iBook: Processor Cycling

Processor cycling is an energy-saving feature built into PowerBook and iBook computers. It increases battery life by slowing down the processor when the computer is not being used. Processor cycling slows the processor to approximately 25 percent of its normal speed.

Turning off Processor Cycling

PowerBook and iBook computers come with processor cycling turned on when running on battery power. You can disable processor cycling by following these steps:

1. Open the Energy Saver control panel.

2. Click Advanced Settings.

3. Click the checkbox to deselect the "Allow processor cycling" option.

• moving the mouse
• typing on the keyboard
• saving or reading files on the hard disk
• reading a CD-ROM or DVD-ROM disc

If a program is running and you're not using the mouse, keyboard, hard disk, or CD-ROM/DVD-ROM discs, processor cycling can cause the program to slow. For example, Macromedia Flash animations, which run entirely from RAM, may become choppy due to processor cycling.