Specifications

In addition, the Power Mac G5 computer allows the user to control bus slewing mode. The options for specifying

either high, reduced, or automatic processor and bus speeds are located at System Preferences>Energy

Saver>Options; then select Automatic, Highest, or Reduced.

Note: For best performance when using professional applications with high demand on the system

(such as Final Cut Pro or Logic), you may want to set the processor/bus speed option to highest.

If the Power Mac G5 computer detects a processor temperature that is high, due to high ambient temperatures

or other factors, it will automatically enter bus slewing mode regardless of the selected setting.

Processor States

The following processor states are defined:

●

Run: The system is running at maximum processing capacity with all processors running at full speed.

●

Idle: The system is idling; this is the default state. All clocks are running and the system can return to

running code within a few nanoseconds. If the system has no work to do, it will be in idle mode.

System Modes

The Macintosh system has the following power-saving modes. If the system does not support full sleep, it will

use the less efficient doze mode.

●

Run: The system is fully functional in normal operating mode with all components powered and operating.

●

Doze: The power to the disk drive motors and the display is turned off, but the power supply and fans are

still on. PCI cards that don't support full system sleep (some SCSI cards, some graphics cards) will cause

the machine to doze rather than fully sleep.

●

Full sleep: The main power supply is shut down. A trickle supply provides auxiliary power to the PCI slots

and keeps the DRAM state preserved for a quick recovery. All processors are powered off with their state

preserved in DRAM. All non-essential clocks in the system are suspended. This mode allows the computer

to meet Energy Star sleep requirements while providing the ability to start up without rebooting. This

system may be awakened by administrative network packets, keyboard or mouse activity, USB device

insertion or removal, or PMU scheduled wakeup.

●

Off: The Power Mac G5 computer meets FEMP (Federal Energy Management Program) requirements and

supports FireWire ports functioning as repeaters when operating on AC power.

Overview to the Power Mac G5

System Software