Where did the computer go? It’s behind the flat panel display in the iMac G5! And the mouse and keyboard are available as wireless models with Bluetooth (which remains optional and can only be installed at the factory) – that means less cable clutter than most users are used to.

Not just smaller and lighter, the iMac G5 is also quieter than the iMac G4 – by 25 dB! And for those who want to save more desktop space, the iMac G5 works with industry standard (VESA compliant) arms for mounting on the wall, a swing-away arm, etc.

This model ships standard with the Nvidia FX GeForce 5200 Ultra across the board, the same GPU that came with the final 17/20″ iMac G4. Although within the system profiler however, the Mac self-reports that it has a GeForce FX 5200 non-ultra. It also introduces faster, PC-3200 400 MHz DDR RAM for this model year. Models sold in North America and Japan are single voltage, while those sold in the rest of the world support both 110 and 220 volt current.

Capacitor Plague

Between 1997 and 2007, a new type of electrolytic capacitor was developed which were water-based, low-impedance, low ESR, and high ripple current – properties which were suitable for power supply design. Unfortunately, there was a higher than expected rate of failure due to electrolyte decomposition which caused corrosion and gas buildup which would rupture the capacitor and typically rendered devices unusable. These water based caps made aluminum hydroxide which reacted with the cap cans, reacting to produce hydrogen. The pressure would continue building until the stamped-in “vent” would burst. Although some devices in the ’90s experienced this, it wasn’t truly until 2002 where the issue had become prevalent. This problem affected a vast swathe of manufacturers, affected multiple Mac models, but disproportionately affected the iMac G5 giving it a terrible reputation. (Brian Benchoff, Ask Hackaday: experiences with capacitor failure, retrieved 1/13/2025, URL)

PowerPC 970 fx and Strained Silicon

Although some online sources report the iMac G5 as having a PowerPC 970 CPU, it actually has a PowerPC 970 fx CPU – as reported by Geekbench 2 and Wikipedia. While this may not make a substantial difference to the average user, there are some differences between the 970 and 970 fx – most notably power consumption. This led many to believe at the time it was actually possible to stuff a G5 into the notebook, all the while they were producing too much heat even for the computers they were already made with. The 970 fx uses a 90 nm fabrication process versus the 970’s 130 nm process, and incorporates a new technique called strained silicon. Strained silicon is a stretched lattice of silicon atoms, which chip makers used to improve the ability of electrons to flow through the semiconducting material. Transistors made from strained silicon are claimed to have a 35% performance improvement over transistors of the same size made without. (See More)

A design trendsetter

This was the very first iMac to have this form factor – a display attached to an L-shaped stand, ports in the back, big chin on the bottom. Despite iterative changes, this design holds up even to this day, with the Apple Silicon iMacs. The iMac G5 lived a short 2-ish years on the market, surviving two model updates before being discontinued on March 20th, 2006.

(Above, from left to right: 2004 iMac G5, 2011 27″ iMac, 2024 M4 iMac)

What You Need To Know

• This iMac G5 has the Serial-ATA 1.0 standard, so it’s not limited to the 128GB drive limitation of earlier models.
• The bootable drive size limit for this model is 2.19 TB, via the Apple Partition Map. This iMac G5 can read and write (but cannot boot) from any size GUID partition table drive.
• Typically the point of failure in the iMac G5 are the capacitors. Once replaced, it should be up and running just as it was before.

Details

• Announced August 31st, 2004
• Apple model number: A1058 (EMC 1989) – 17″
  • A1076 (EMC 2008) – 20″
• Model ID: PowerMac8,1
• Order Number: M9248LL/A (1.6, 17″)
  • M9249LL/A (1.8, 17″)
  • M9250LL/A (1.8, 20″)
• Discontinued on May 3rd, 2005

How it stacks up in Geekbench 2.4.3

• 842 (1.6 17″ G5) / 985 (1.8 17″ or 20″ G5) / 918 (1.6 SP Power Mac G5)

Unsupported Mac OS X

• Although it is not officially supported, the iMac G5 can run Mac OS X 10.6.8 Snow Leopard using a MacRumors community developed build. It is currently still in development based off the Darwin 10.8.0 kernel compiled from source. See LEM Article.

Mac OS X

• Requires Mac OS X 10.3.5 (Build 7P35) Panther through Mac OS X 10.5.8.

Core System

This iMac G5 shipped with an IBM PowerPC G5 970fx 90nm CPU. System Bus is 1/3 of the installed CPU speed, CPU is soldiered using a 576-pin cBGA package.

Legend: L1i = L1 Instruction Cache, L1d = L1 Data cache

• ($1299): 1.6 Ghz, 1 Processor, 1 Core, 1 Thread, 1 Core Per-CPU, 64-Bit
  29W TDP, 64KB L1i, 32KB L1d, 512KB L2, 58M Transistors, FSB: 533 MHz
  CPU Instructions: Altivec, FP, VMX, VMX128, AND, XOR, OR
  .
• ($1499+): 1.8 Ghz, 1 Processor, 1 Core, 1 Thread, 1 Core Per-CPU, 64-Bit
  38W TDP, 64KB L1i, 32KB L1d, 512KB L2, 58M Transistors, FSB: 600 Mhz
  CPU Instructions: Altivec, FP, VMX, VMX128, AND, XOR, OR
  .
• ROM: 1 MB Open Firmware ROM, other instructions loaded into RAM.

Video

Mini-VGA to VGA and Composite/S-Video adapters sold separately.

• (All): GeForce FX 5200 Ultra, 64 MB DDR SDRAM @6.4 GB/s, Rankine, 128-Bit Bus
  • 45 Million Transistors, 150 nm process size, AGP 4x @ 1066 MB/s,
  • 250 MHz GPU clock, 200 MHz Memory clock (400 Mb/s effective), ~32W TDP
  • 4 Pixel Shaders, 4 TMUs, 4 ROPs, DX9.0a, OpenGL 1.5/2, Pixel 2 Vertex 2
    .
• ($1299/1499): Built-In 17″ Active Matrix, TFT (Thin Film Transistor), CCFL-Backlit LCD Display with a native resolution at 1440 x 900 @ 200 candela per square meter (200 nits), 99 PPI
  • “Simultaneously supports the built-in display, millions of colors with a Mirror display setup with a maximum resolution of 1024 x 768″
    .
• ($1899): Built-In 20″ Active Matrix, TFT (Thin Film Transistor), CCFL-Backlit LCD Display with a native resolution at 1680 x 1050 @ 200 candela per square meter (200 nits), 99 PPI
  • “Simultaneously supports the built-in display, millions of colors with a Mirror display setup with a maximum resolution of 1024 x 768″
    .
• Unofficially, screen-spanning and dual-display setups can be manually enabled using a 3rd party app called Screen Spanning Doctor.

Memory

• (All): 256 MB 400 MHz PC-3200 DDR SDRAM ~3.2 GB/s
  • Configurable to 2 GB through Apple.

Drives

• ($1299): 80 GB 7200 rpm Serial-ATA 1.0 (1.5 Gb/s) Hard Disk Drive
  • 8x Combo Drive (Write: 24x CD-R, 16x CD-RW)
    (Read: 8x DVD, 24x CD)
    .
• ($1499): 80 GB 7200 rpm Serial-ATA 1.0 (1.5 Gb/s) Hard Disk Drive
  • 4X SuperDrive (Write: DVD-R 4x, CD-R 16x, CD-RW 8x)
    (Read: DVD 8x, CDs 32x)
    .
• ($1899): 160 GB 7200 rpm Serial-ATA 1.0 (1.5 Gb/s) Hard Disk Drive
  • 4X SuperDrive (Write: DVD-R 4x, CD-R 16x, CD-RW 8x)
    (Read: DVD 8x, CDs 32x)

Expansion/Misc

• 3x USB-A style USB 2.0 ports
• 2x FireWire 400
• 1x Mini-VGA Port
  • Adapters sold separately
• 56k v.92 Modem (RJ-11 style connector)
• 100 Mb/s Base-T Ethernet (RJ-45 style connector)
  • Optional WiFi: IEEE 802.11g AirPort Extreme (Wifi 3, 54 Mb/s)
  • Optional Bluetooth 1.1
• Singular Internal Microphone
• Power supply: 130W
• PRAM battery: 3.6V half-AA
• 3.5 mm Headphone Jack
  • (Optical and Digital audio)
• 3.5 mm Microphone Jack
• 1x standard 3-prong IEC 63020 Power connector
• Kensington Security Lock

Physical

• H x W x D (17″): 16.9 x 16.8 x 6.8 in/43 x 42.6 x 17.3 cm
  • H x W x D (20″): 18.6 x 19.4 x 7.4 in/47.2 x 49.3 x 18.9 cm
• Weight (17″): 18.5 lb/8.4 kg
  • Weight (20″): 25.2 lb/11.4 kg

Included In Box

• iMac G5 17″ ($1299/1499)
  • iMac G5 20″ ($1899)
• Styrofoam to hold the iMac in place
• Foamy protective cover for iMac G5
• A1048 White Apple Wired USB Keyboard
• M5769 White Apple Wired USB Mouse
• White Apple IEC 63020 to NEMA 5-15 3-prong power cord
• iLife box may or may not be included
• White Apple Remote A1156
• “Congratulations on your new Mac. Now Load it up” box/holder
  • AppleCare protection plan disc
  • Software restore discs
• Apple Stickers
• Apple Computer, Inc 1 Year Limited Warranty – Worldwide
• Software License Agreement for Mac OS X – Single Use License booklet
• Software coupons for iLife and Mac OS X Panther
• AirPort Extreme and regulatory information if configured with Airport

LEM Mail lists

• Got an iMac? Join our iMac Group or iMacs & eMacs Forum.
• Our Mac OS 9 Group is for those using Mac OS 9, either natively or in Classic Mode.
• Our Panther Group is for those using Mac OS X 10.3.
• Our Tiger Group is for those using Mac OS X 10.4.
• Our Leopard Group is for those using Mac OS X 10.5 and 10.6.

Online Resources

• Full list of online resources for the iMac G5 (2004) on a separate page.