FireWire 800 Power Mac G4

The January 2003 Power Mac G4 was the first to require OS X. It was also the first with FireWire 800 ports. A good rule of thumb: If it has FireWire 800, it isn’t meant to boot OS 9, although we have heard of a workaround. The FireWire 800 model was also the first Power Mac with a Bluetooth socket and support for 802.11g AirPort Extreme.

FireWire 800 Power Mac G4Apple hit the 1 GHz mark in January 2002, 1.25 GHz in August 2002, and 1.42 GHz in January 2003. At the bottom of the new series, Apple dispensed with dual processors to keep the price down – the 1.0 GHz single CPU model retailed for just $1,499.

Still, Motorola remained “behind the curve” with G4 processor speeds, which, extrapolated from Moore’s Law, should have increased roughly 25% every six months. Instead, we had a decidedly overhyped 14% jump in CPU clock speed. On the other hand, the price is 18% lower than the MDD model, further improving the value of the Power Mac G4.

As with the MDD, the two faster versions have a 167 MHz system bus. All models have two media drives bays (so you can have a SuperDrive and a fast CD burner or a second SuperDrive), four RAM sockets, and three independent drive buses that each support two devices. An Ultra ATA/33 (ATA-4) bus is used for the optical drive(s), Ultra ATA/100 (ATA-6) connects to the stock hard drive, and there’s also a normally unused Ultra ATA/66 (ATA-5) bus. Only the ATA/100 connector supports drives over 128 GB capacity. There are four 3.5″ hard drive bays inside the G4.

The fastest pair of new G4s have faster video cards, the ATI Radeon 9000. The dual 1.42 GHz model includes 2 MB of level 3 cache per processor, twice as much as the slower models.

Beware Apple’s claim of “four USB ports” – there are two on the computer and two on the keyboard, so once you’ve plugged in the keyboard, you’re down to three available. Make that two after you plug in the mouse. Your best bet here is to add a USB 2.0 PCI card, which also overcomes the speed limitations of this model’s built-in USB 1.1 ports. has documented a process for downgrading the firmware of this model so it can natively boot Mac OS 9. We’re hoping to find someone who has done the procedure who can distill this long thread into a more easily followed step-by-step process.

Keeping It Cool

Two CPUs can run fairly hot. Use good thermal paste (Arctic Silver is one, and you should probably reapply every few years) or a really good thermal pad. Consider replacing some of the fans with ones that move more air (and, in some cases, will also reduce fan noise).

The Power Mac G4 (FW800) uses a copper heatsink, and The House of Moth has tested it against the aluminum heatsink used in the original MDD model. The copper heatsink runs cooler by roughly 5°F (2.7°C). If you need/want a Mac that still natively boots Mac OS 9, this is one more thing to help it keep its cool.

A Better Video Card

For everyday use, the stock video cards are just fine, but if you’re into gaming with this PPC Mac, you will want a better video card than the ATI Radeon 9000 Pro, which in some games will drop below 10 FPS. Again, The House of Moth provides an answer. By modifying an ATI Radeon 9650 from a Power Mac G5, performance in the OpenGL benchmark quadrupled compared to the 9000 Pro! This card also has 128 MB or, if you are lucky, 256 MB of video memory, which also helps with gaming performance.

“Games fly, even with all settings maxed out at full resolution. The card does run hot so I keep game settings medium-high until I can whack a fan on it or find another cooling solution.”

But you know gamers: Always looking for improved performance, and when Greg Hrutkay recommended the ATI Radeon X850 Pro with 256 MB of video memory to The House of Moth, they found one on eBay and installed it. As of Sept. 2018, we don’t have any more information on this upgrade, because the video card purchased on eBay is broken.


  • Introduced 2003.01.28 with 1.0 GHz single CPU, 256 MB RAM, 60 GB hard drive, Combo drive, and GeForce 4x graphics at $1,499; reduced to $1,149 on 2003.06.23. 1.25 GHz dual 256 MB/80 GB/Combo/Radeon 9000 introduced at $1,999; reduced to $1,699 on 2003.06.23. 1.42 GHz dual 512 MB/120 GB/SuperDrive/Radeon 9000 introduced at $2,699; reduced to $2,399 on 2003.06.23. Replaced by Power Mac G5 in mid 2003.
  • requires Mac OS X 10.2 Jaguar through 10.5 Leopard
  • CPU: 1.0/1.25/1.42 GHz PowerPC 7455
  • Bus: 133 MHz on 1.0 GHz model, 167 MHz on faster ones
  • Performance:
    • Geekbench 2 (Leopard): unknown (1.42 GHz dual), 1047 (1.25 GHz dual), 576 (1.0 GHz single)
    • Geekbench 2 (Tiger): 1165 (1.42 GHz dual), 1048 (1.25 GHz dual), 570 (1.0 GHz single)
  • RAM: 256/512 MB standard, expandable to 2 GB using PC2100 memory in 4 DIMM slots in 1.0 GHz model, PC2700 memory in faster models
  • Video: Nvidia GeForce 4 on 1.0 GHz model, ATI Radeon 9000 Pro on faster models; DVI and ADC ports, includes DVI-to-VGA adapter
  • VRAM: 64 MB
  • L2 cache: 256 KB on-chip L2 cache
  • L3 cache: 1 MB on 1 GHz model, 1 MB per CPU on 1.25 GHz model, 2 MB per CPU on 1.42 GHz model
  • Hard drive: 60/80/120 GB 7200 rpm ATA/100
  • Combo (CD-RW/DVD) on 1.0 and 1.25 GHz models; SuperDrive standard on 1.42 GHz model, optional on others
  • internal Zip 250 drive (optional)
  • 4 64-bit PCI slots
  • Modem: internal 56k v.92
  • Microphone: standard 3.5mm minijack, compatible with line-level input, not compatible with Apple’s PlainTalk microphone
  • FireWire 400: 2 ports
  • FireWire 800: 1 port
  • USB: 2 USB 1.1 ports
  • Ethernet: 10/100/gigabit
  • WiFi: antenna and connector for 802.11g AirPort Extreme card
  • size (HxWxD): 17.0″ x 8.9″ x 18.4″
  • Weight: 42.0 lb.
  • Gestalt ID: n/a
  • PRAM battery: 3.6V half-AA
  • upgrade path: none yet, although CPU upgrades are likely
  • Part no.: M8689 (1 GHz), M8840 (1.25 GHz), M8841 (1.42 GHz)

Accelerators & Upgrades

Online Resource



  • Leopard (Mac OS X 10.5) boot times for Power Mac with the GeForce 6200 fall into the 4-5 minute range, and was initially suggested that you install Leopard with the Mac’s original video card to avoid slowing down the process. “gotoh” has posted the fix in The Mac Elite Forum. The delay is due to Leopard not supporting temperature sensors in G4 Macs. Simply remove AppleHWSensor.kext from /System/Library/Extensions, and the delay goes away.
  • Note that some vendors are substituting PC2700 RAM for PC2100 modules. Although PC2100 Macs can work with PC2700 RAM, you can’t use both types of RAM in the same machine. All installed RAM must be the same type, whether PC2100 or PC2700.

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