Power Mac G5 Dual (Late 2005)

The first Macs to use IBM’s new dual-core G5 CPUs, the Late 2005 Power Mac G5 Duals and Quad (covered on its own page) provide the processing power of two G5 CPUs on a single chip. Each core has 1 MB of level 2 cache, twice as much as earlier G5s, which further boosts computing power.

Power Mac G5Other improvements include the adoption of PCI Express (PCIe) architecture and a 16-lane Nvidia video card, 533 MHz DDR2 memory, and a 16x dual-layer SuperDrive.

The motherboard architecture uses HyperTransport technology. System memory is so fast (533 MHz RAM on a 1.0 or 1.15 GHz bus) and the level 2 cache so large that Apple doesn’t bother with a level 3 cache.

And if a single dual-core G5 CPU isn’t enough for you, there’s always the 2.5 GHz Power Mac G5 Quad, which has two dual-core liquid-cooled CPUs and was Apple’s most powerful PowerPC Mac.

A headphone jack, a USB 2.0 port, and a FireWire 400 port are located on the front of the G5 for easy access, and there are three USB ports on the back, up from two on previous G5 Power Macs.

rear of Power Mac G5 and G5 DualIt’s easier to distinguish the dual-core models from the earlier ones from the back than from the front, as shown in the photo on the left. The Dual and Quad (left) have three USB ports at the bottom of the strip of ports, while earlier models (right) have ethernet and modem at the bottom. The dual-core machines also have a grey plastic strip on the left side.

Power plug on dual-core Power Mac G5One oddity of the dual-core Power Mac G5s is that they use a different power connection, known as IEC320 C19, and don’t work with the standard computer power cable, as show in the photo on the right. These models also use a different power supply than earlier G5 Power Macs.

Power Mac G5 Reliability

Reliability ratings are based on statistics compiled by MacInTouch in June 2006, at which time the dual-core Power Mac G5 models had only been on the market for 8 months. Letter grades are based on failure rate: A = 0-6%, B = 7-12%, C = 13-18%, D = 19-24%, and F = 25% or higher. We also note the two components that failed most often.

  • G5/2.0 dual-core, C- (18%, power supply, logicboard)
  • G5/2.3 dual-core, C- (18%, power supply, logicboard or optical drive)
  • G5/2.5 quad-core, C- (17%, logicboard, power supply)

In each generation, except for the final dual-core one, the fastest model is the least reliable, while the second-fastest is the most reliable. Logicboards are the most expensive component to repair, followed by the power supply. Hard drives, optical drives, video cards, and RAM can be replaced inexpensively using third-party components.

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  • introduced 2005.10.19 with 2.0 GHz at $1,999, 2.3 GHz at $2,499; replaced by 2006 Mac Pro on 2006.08.07
  • Supported Mac OS Versions
  • CPU: 2.0/2.3 GHz dual-core G5
  • Bus: 1.0 GHz/1.15 GHz (half CPU speed)
  • Performance:
    • Geekbench 2 (Leopard): 2007 (2.3 GHz), 1781 (2.0 GHz)
    • Geekbench 2 (Tiger): 2066 (2.3 GHz), 1828 (2.0 GHz)
  • RAM: 512 MB, expandable to 16 GB using 533 MHz PC2-4200 DDR2 RAM in 8 slots
  • L2 cache: 1 MB on-chip L2 cache per core
  • L3 cache: none
  • Video: Nvidia GeForce 6600 LE. Nvidia 7800 GT with 256 MB and Nvidia Quadro FX 4500 with 512 MB optional
  • VRAM: 128 MB (2.0 GHz) or 256 MB (2.3 GHz)
  • Hard drive bus: 1.5 Gbps SATA Rev. 1
  • Hard drive: 160/250 Serial ATA (SATA) 7200 rpm
  • Optical drive bus: ATA/100 bus
  • optical drive: 16x dual-layer SuperDrive on Ultra ATA/100 bus
  • 3 open PCI Express slots: two 4-lane slots, one 8-lane slot
  • optional external 56k v.92 modem
  • Microphone: standard 3.5mm minijack, compatible with line-level input, not compatible with Apple’s PlainTalk microphone
  • FireWire: 2 FW400 ports (1 on front), 1 FW800 port
  • USB: 4 USB 2.0 ports (1 on front)
  • Ethernet: 2 independent 10/100/gigabit ports
  • WiFi: antenna and connector for 802.11g AirPort Extreme card
  • Bluetooth: built in, optional antenna
  • size (HxWxD): 20.1″ x 8.1″ x 18.7″ (51.1 x 20.6 x 47.5 cm)
  • Weight: 44.5-48.8 lb. (20.2-22.1 kg)
  • Gestalt ID: n/a
  • PRAM battery: 3V CR2032 lithium
  • power supply: 450W 661-3737, requires IEC320 C19 power cord
  • Part no.: M9590 (2.0 GHz), M9591 (2.3 GHz)

Accelerators & Upgrades

  • none

Online Resources

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