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Overview to the Power Mac G5
The 64-bit desktop Power Mac G5 uses dual PowerPC G5 microprocessors and is intended for use in content creation, desktop publishing, multimedia, scientific and technical applications, and other activities that require high performance.
New Hardware Features
Below is a list of the new hardware features of the Power Mac G5. A list of all hardware features is provided in Hardware Features Summary.
Microprocessors: The Power Mac G5 computer is available in dual 2.0 GHz, 2.3 GHz, and 2.7 GHz configurations. For more information, see PowerPC G5 Microprocessor.
Graphics card: The Power Mac G5 computer comes standard with one of the following graphics cards: the ATI Radeon 9600 with 128 MB RAM or the ATI Radeon 9650 with 256 MB RAM. The NVIDIA GeForce 6800 Ultra DDL with 256 MB RAM is a build-to-order option. For more information, see Graphics Cards.
Hard disks: An internal 7200 rpm Serial ATA (SATA) hard disk occupies one of two drive bays and functions as the default boot disk. A second SATA drive is available as a build-to-order option. Hard disk capacities are 160 GB, 250 GB, and a 400 GB build-to-order option. For more information, see Serial ATA Interface.
Power supply: The Power Mac G5 computer comes with a 450 W or 600 W power supply.
SuperDrive (DVD+R DL/DVD+/-RW/CD-RW): The Power Mac G5 computer has a 16x SuperDrive connected to the Ultra DMA ATA/100 bus. The SuperDrive supports DVR+R double-layer (DL) format. For more information, see SuperDrive.
Bluetooth 2.0 + EDR: Available as a build-to-order option or as an Apple Authorized Service Provider kit. The fully-integrated Bluetooth 2.0 module with enhanced data rate (EDR) enables short-range wireless connections between desktop and laptop computers and a host of other peripheral devices. For more information, see Bluetooth Technology.
Hardware Features Summary
Below is a list of all of the hardware features of the Power Mac G5. The major features are described more fully later in this note. To view the Technology and Performance Overview document, refer to http://www.apple.com/powermac/.
Microprocessors: The Power Mac G5 computer is available in dual 2.0 GHz, 2.3 GHz, and 2.7 GHz configurations. For more information, see PowerPC G5 Microprocessor.
Processor system bus: The processor interface system bus runs at half the speed of the system microprocessor. For more information, see Processor Bus.
Memory caches: The PowerPC G5 microprocessors used in the Power Mac G5 computer have an internal 512 KB level 2 cache.
Memory bus: The main memory bus is 128 bit 400 MHz. For more information, see Main Memory Bus.
DDR SDRAM: Depending on configuration, the Power Mac G5 has four or eight DIMM slots for 184 pin DIMMs (dual inline memory modules) using unbuffered DDR (double data rate) SDRAM 64-bit, 400 MHz (PC3200) devices for a maximum of 4 GB or 8 GB. For more information, see Main Memory Bus.
Liquid cooling system: One configuration has a liquid cooling system. For more information, see Liquid Cooling System.
AGP 8x Pro slot: The computer has an AGP 8x Pro slot with an accelerated graphics card installed. For more information, see Accelerated Graphics Port Bus.
PCI expansion slots: Some configurations support three 64-bit 33 MHz PCI slots. For more information, see PCI or PCI-X Expansion Slots.
PCI-X expansion slots: Some configurations support three PCI-X expansion slots: one slot supports a maximum of 133 MHz and two slots support a maximum of 100 MHz. For more information, see PCI or PCI-X Expansion Slots.
Hyper Transport bus: The Power Mac G5 supports the high-speed bus architecture between the memory controller and device I/O. For more information, see HyperTransport Technology.
Graphics card: The Power Mac G5 computer comes standard with one of the following graphics cards: the ATI Radeon 9600 with 128 MB RAM or the ATI Radeon 9650 with 256 MB RAM. The NVIDIA GeForce 6800 Ultra DDL with 256 MB RAM is a build-to-order option.For more information, see Graphics Cards.
Hard disks: An internal 7200 rpm Serial ATA (SATA) hard disk occupies one of two drive bays and functions as the default boot disk. A second SATA drive is available as a build-to-order option. Hard disk capacities are 160 GB, 250 GB, and a 400 GB build-to-order option. For more information, see Serial ATA Interface.
Power supply: The Power Mac G5 computer comes with a 450 W or 600 W power supply.
SuperDrive (DVD+R DL/DVD+/-RW/CD-RW): The Power Mac G5 computer has a 16x SuperDrive connected to the Ultra DMA ATA/100 bus. The SuperDrive supports DVR+R double-layer (DL) format. For more information, see SuperDrive.
Combo (DVD-ROM/CD-RW) drive: Instead of a SuperDrive, the Power Mac G5 computer has an optional build-to-order combination DVD-ROM/CD-RW drive connected to the Ultra DMA ATA/100 bus. For more information, see Combo Drive.
High-speed USB 2.0: The computer has three external USB 2.0 ports: two on the rear of the enclosure and one on the front. All ports support both high-speed and classic USB speeds. For more information, see USB Ports.
Ethernet: The computer has a built-in Ethernet port for 10Base-T/UTP, 100Base-TX, or 1000Base-T Gigabit operation. The Ethernet port is auto-sensing and self-configuring to allow use of either a cross-over or straight-through cable. For more information, see Ethernet Port.
AirPort Extreme Card: Available as a build-to-order option, the 54 Mbps AirPort Extreme Card provides a wireless LAN connection. For more information, see Wireless LAN Module.
Bluetooth 2.0+ EDR: Available as a build-to-order option or as an Apple Authorized Service Provider kit. The fully-integrated Bluetooth 2.0 module with enhanced data rate (EDR) enables short-range wireless connections between desktop and laptop computers and a host of other peripheral devices. For more information, see Bluetooth Technology.
FireWire ports: The computer has two FireWire 400 ports and one FireWire 800 port. For more information, see FireWire Controllers.
Modem: The built-in Apple 56 Kbps modem is available as a build-to-order option or as an Apple Authorized Service Provider kit. The modem supports K56flex and V.90 and V.92 modem standards. For more information, see Internal Modem.
Keyboard: The computer comes with a full-size USB Apple Keyboard. The keyboard is also a bus-powered USB hub with two USB ports. For more information, see Keyboard.
Mouse: The computer comes with a USB Apple Mouse, with optical tracking. For more information, see Mouse.
Boot ROM: The Power Mac G5 computer comes with 1 MB of boot ROM.
Optical digital audio: The Power Mac G5 implements optical digital audio I/O via S/PDIF (Sony/Phillips Digital Interface) TOSLink input and output connectors on the rear panel. For more information, see Sound System Overview.
Analog audio line-in: Rear panel analog audio line-in port for self-powered microphones or other audio equipment. For more information, see Audio Line-in.
Analog audio line-out: Rear panel analog audio line-out port for externally-powered speakers or other audio devices with line-level outputs. For more information, see Audio Line-out.
Headphone and internal speaker: The front panel includes a headphone mini-jack and the system includes an internal front mono speaker. For more information, see Headphone Jack.
DVI to video adapter: The Power Mac G5 supports S-video and composite video from an optional adapter connected to the DVI port. For more information, see DVI to Video Adapter.
Voltage switching: Auto-ranging voltage switching accepts 100 - 240V.
Fan speed control: The speeds of the fans are controlled by thermal/wattage factors and are automatically set as low as possible to minimize noise.
Dimensions and weight: Power Mac G5 dimensions are 20.12” (51.1 cm) high by 8.11” (20.6 cm) wide by 18.70” (47.5 cm) deep and weighs approximately 44.4 pounds (20.2 kg).
Energy saving: Sleep scheduling can be controlled via the Energy Saver pane in System Preferences.
Features of the Enclosure
The Power Mac G5 computer’s enclosure is a tower design. Figure 1-1 illustrates the front of the enclosure and Figure 1-2 illustrates the rear of the enclosure.
The enclosure has space for two hard disk drives and one optical device. See Hard Disk Drives.
To access the main logic board to install PCI or PCI-X cards or additional memory, refer to Expansion. For full details regarding opening and accessing the computer, refer to the Power Mac G5 User’s Guide that was shipped with your computer.
System Software
The Power Mac G5 ships with Mac OS X 10.4 installed as the default operating system. The classic environment can be used to run Mac OS 9 applications. Load the Classic application from the system software optical disk that shipped with your computer.
To retrieve information from the I/O Registry, use the APIs in the header file IOKit/IOKitLib.h.
Computer Identification
Rather than reading the box flag or the model string and then making assumptions about the computer’s features, applications that need to find out the features of the computer should use I/O Registry calls to test for the features they require.
Asset management software that reports the kind of computer it is run on can obtain the value of the property at Devices:device-tree:compatible in the IODeviceTree plane of the I/O Registry. The model string is the first program-usable string in the array of C strings in the compatible field. For the Power Mac G5 2.0 GHz and 2.3 GHz configurations, the value of the model property is PowerMac7,2 ; the 2.7 GHz configuration model property value is PowerMac7,3 .
Power Management
The basics of Power Mac G5’s power management techniques are described in the following paragraphs.
Processor and Bus Slewing
To lower power consumption, heat generation, and fan noise, the Power Mac G5 computer incorporates an automatic power management technique called bus slewing. Bus slewing is designed to run at high processor/bus speeds and high voltage when the demand on the processor is high, and to run at low processor/bus speeds and low voltage when the demand on the processor is low.
Switching between different processor/bus speeds and voltages is achieved by a gradual transition that is designed to minimally impact system or application performance and typically operates seamlessly to the user. In slewing, the bus runs at half the speed of the processor.
The ranges of the slewed processor speeds are listed below:
Configuration | Processor range |
|---|---|
2.0 GHz | 1.8 GHz to 2.0 GHz |
2.3 GHz | 1.8 GHz to 2.3 GHz |
2.7 GHz | 2.0 GHz to 2.7 GHz |
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.
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.
Velocity Engine Acceleration
The Velocity Engine is the vector processing unit in the PowerPC G5 microprocessor. System software has been modified to take advantage of the accelerated processing that the Velocity Engine makes possible and to support low-level operations using the Velocity Engine.
For complete information on the Velocity Engine, refer to the following Apple website:
Copyright © 2003, 2005 Apple Computer, Inc. All Rights Reserved. Terms of Use | Privacy Policy | Updated: 2005-04-29