20″ iMac G5 (Mid 2005)

iMac G5The May 2005 revision of the iMac G5 got a 200 MHz speed boost, bringing it to 2.0 GHz. Other improvements include an 8x dual-layer SuperDrive, better video, gigabit ethernet, and an ambient light sensor (ALS).

512 MB of RAM is now standard across the line, making the entry-level model more responsive and possibly saving many users the expense of a memory upgrade. The 20″ iMac now has a 250 GB drive.

Apple has replaced the Nvidia graphics of the original iMac G5 and adopted the ATI Radeon 9600, which includes 128 MB of video memory (twice as much as in the 2004 model).

Bluetooth and AirPort Extreme are standard features on the Mid 2005 iMac G5.

  • 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 Tiger Group and Tiger Forum are for those using Mac OS X 10.4.
  • Our Leopard Forum is for those using Mac OS X 10.5.
  • Our Leopard Group is for those using Mac OS X 10.5 and 10.6.

With the 2004 iMac, models sold in North America and Japan were single voltage, while those sold in the rest of the world supported both 110 and 220 volt current. Based on published specs, this seems not to be the case with the 2005 iMac.

The 2005 iMac ships with Mac OS X 10.4 Tiger.


  • introduced 2005.05.03 at US$1,799, replaced by iSight iMacs 2005.10.12.
  • Requires Mac OS X 10.4 through 10.5 Leopard
  • CPU: 2.0 GHz G5
  • Bus: 667 MHz
  • Performance:
    • Geekbench 2 (Leopard): 985 (2.0 GHz)
    • Geekbench 2 (Tiger): 1176 (2.0 GHz)
  • RAM: 512 MB, expandable to 2 GB using PC3200 (400 MHz) DDR SDRAM
  • Graphics: ATI Radeon 9600 with AGP 8x support
  • Display: 20″ 1680 x 1050 flat panel display
  • Video out: VGA, S-video (requires adapter)
  • L2 cache: 512 KB on CPU
  • Hard drive bus: 1.5 Mbps SATA I
  • Hard drive: 250 GB 7200 rpm SATA drive
  • Optical drive bus: UltraATA
  • SuperDrive: writes DVD±R discs at up to 8x speed, dual layer at up to 2.4x; DVD±RW at up to 4x; reads DVDs at up to 8x, writes CD-R discs at up to 24x, writes CD-RW discs at up to 8x, reads CDs at up to 24x
  • USB: 3 USB 2.0 ports
  • FireWire 400: 2 ports
  • Modem: built-in 56 kbps modem supports v.92 standard
  • Ethernet: 10/100/gigabit
  • WiFi: 802.11g AirPort Extreme included
  • Bluetooth: included
  • Microphone: internal
  • Power supply: 130W
  • H x W x D: 18.6 x 19.4 x 7.4 in/47.2 x 49.3 x 18.9 cm
  • Weight: 25.2 lb/11.4 kg
  • Part no.: M9845
  • Model identifier: PowerMac8,2

CPU Upgrades

  • none

Online Resources