Being released a little over 2 months after the 15/17″ variants of the late 2003 refresh, this was the latest and greatest iMac G4 to-date (as well as the largest). Featuring a brand new 20″ TFT (thin film transistor) active matrix 1680 x 1050 LCD display, the sheer weight of the screen required a heavier base to counterbalance it. At 40.1 pounds, this is the heaviest iMac G4 yet. With the exception of the screen size and weight, the 20″ iMac G4 is identical to the Late 2003 17″ model. This was the first iMac to have USB 2.0, and it got a slight RAM upgrade to PC-2700 333 MHz DDR over the Early 2003 17″ iMac’s PC-2100 266 MHz DDR.

Introducing USB 2.0 to the iMac

USB 2.0 made a gargantuan leap up to a maximum speed of 480 Mb/s, over USB 1.1’s 12 Mb/s. This made it far more suitable for file transfers, managing digital media, connecting digital cameras, and all other forms of external media. USB 2.0 is literally 40 times faster over even the “higher speed” 12 Mb/s specification of USB 1.1, making it a total night and day difference versus what was offered on previous iMac models. The iMac features three USB-A style USB 2.0 ports, making all the available ports run at this newer specification.

Strongest GPU in an iMac G4, too.

The NVIDIA GeForce FX 5200 Ultra graphics chip is shared between the 17″ and 20″ model, and is the highest end GPU ever paired with an iMac G4. It runs on TSMC’s 150 nanometer process, runs off of an AGP 4x bus within the iMac sporting 64 MB of DDR, and consumes a maximum of 32 watts of power. This makes it a more power hungry component than even the iMac G4’s CPU, which tops out between 26.5w and 27w TDP.

What You Need To Know

• This iMac G4 has the ATA/100 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 G4 can read and write (but cannot boot) from any size GUID partition table drive.
• Time has proven this is a very sought-after variant of the iMac G4, as it is the highest configured, has the largest screen, and hardest to find.

Details

• Announced November 18th, 2003
• Apple model number: A1065 (EMC 1992)
• Model ID: PowerMac6,3
• Order Number: M9290LL/A
• Nickname: iLamp
• Discontinued on July 1st, 2004

How it stacks up in Geekbench

• Version 2.4.3: 576 (1 Ghz) / 616 (20″ 1.25) / 918 (1.6 SP G5)

Unsupported Mac OS 9/ Mac OS X

• Although it is not officially supported, the 20″ iMac G4 1.25 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.
• It is also possible to install Mac OS 9 “unofficially” using a “Mac OS 9 Lives!” disk image.

Mac OS X

• Requires Mac OS X 10.3.1 Panther through Mac OS X 10.5.8.

Core System

This iMac G4 shipped with a PowerPC G4 Motorola 7445 180nm CPU. System Bus is 167 MHz, and the CPU is soldiered (not on any card or socket).

• ($2199): 1.25 Ghz, 1 Processor, 1 Core, 1 Thread, 1 Core Per-CPU
  ~27W TDP, 64KB L1, 256KB L2, 33M Transistors, No L3 Present
  CPU Instructions: Altivec Velocity Engine, VMX, VMX128, AND, XOR, OR
  .
• ROM: 1 MB Open Firmware ROM, other instructions loaded into RAM.

Video

• ($2199): GeForce 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
    .
• Built-In 20″ Active Matrix, TFT (Thin Film Transistor), CCFL-Backlit LCD Display with a native resolution at 1680 x 1050.
  • “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

• 256 MB 333 MHz PC-2700 DDR SDRAM ~2.666 GB/s
  • Configurable to 1 GB through Apple, unofficially can use 2 GB.

Drives

• 80 GB 4200 rpm ATA/100 IDE (ATA-6)
• 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
• Kensington Security Lock
• 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
• 3.5 mm Headphone Jack
• 3.5 mm Microphone Jack
• 1x Speaker “Mini Jack” for Apple speakers
• Singular Internal Microphone
• “Mickey Mouse” style 3-prong IEC 320-C5 Power Connector
• Kensington Security Lock
• Power supply: 130W
• PRAM battery: 3.6V half-AA

Physical

• size:H/W/D 13.93 x 20.9 x 10.6 in/35.4 x 44.0 x 27 cm (Min)
  • Monitor Raised: H/W/D 20.9 x 20.2 x 17.3 in
• Weight: 40.1 lb./18.2 kg

Included In Box

• iMac G4 20″
  • A1048 White Apple Wired USB Keyboard
  • M5769 White Apple Wired USB Mouse
  • Apple Pro “clear” Speakers
• “Mickey Mouse” style 3-prong IEC 320-C5 Power Cord
• “Welcome to Panther” Guide
• Apple Stickers
• Apple Computer, Inc 1 Year Limited Warranty – Worldwide
• Software License Agreement for Mac OS X – Single Use License booklet
• iMac User’s Guide
• Installing iLife guide
• iMac G4 20″ Software Restore Discs
• Designed By Apple in California packet
• Software Coupons

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 20″ iMac G4 (Late 2003) on a separate page.