The Future of 'Digital Audio' Power Macs in the Age of Leopard

The earliest G4 Power Macs had a 100 MHz system bus and ATI Rage 128 graphics on a fast PCI or AGP 2x bus. The following generation of Power Macs adopted a 133 MHz system bus and included AGP 4x graphics. The "Digital Audio" models were the first Macs to offer Radeon and GeForce2 MX graphics processors.

With Mac OS X 10.5 "Leopard" rumored to require a G4 CPU, these are among the oldest Power Macs that might run it - and with recent claims that Leopard will require an 867 MHz CPU, that may only be possible with a CPU upgrade, if at all.

Too Many Models!

Released at Macworld Expo 2001, the Digital Audio Power Mac G4 looked just like its graphite predecessors, but there were several changes on the inside. Where earlier G4 Power Macs had three PCI slots plus an AGP 2x slot, these had four PCI slots and an AGP 4x slot, providing more expansion options and a faster video bus.

Recognizing that it had taken a wrong turn by embracing DVD-ROM drives when the entire PC world was going CD-RW, these were the first Power Macs with CD-RW. That already makes it a challenge for installing Tiger, which normally comes on DVD, but nowadays even 16x SuperDrives are cheap.

Processor speeds ranged from 466 MHz to 733 MHz, and there was a single dual-processor model in the line.

These were the first Power Macs without microphone input.

Entry Level

The least costly of the five models ran at 466 MHz, had ATI Rage 128 Pro video with 16 MB of video memory, and sold for US$1,699. You could optionally order it with an ATI Radeon card, which is the minimum requirement for Quartz Extreme.

The next step up the ladder is the 533 MHz model, which shipped with nVidia GeForce2 MX graphics and 32 MB of video memory for US$2,199.

Two Brains

We consider the dual 533 MHz Digital Audio Power Mac to be the unsung hero of the family. It sold for US$2,499 yet had the processing power to match the $3,499 733 MHz model - at least once Mac OS X became available.

Considering how strongly Apple had hyped "two brains are better than one" in the previous generation, it's surprising that there was only one dual-processor model in this family.

The Top End

At the top was the 733 MHz powerhouse, which was the first Mac to ship with a SuperDrive (a drive that could burn CD and DVDs). It wasn't cheap, and it was the most powerful graphics machine of its time, since very few apps could benefit from the twin CPUs in the dual 533 MHz model.

The Orphan

Maybe Apple felt that the jump between 533 MHz and 733 MHz was too big. Or maybe Motorola had a lot of G4s that didn't pass muster at 733 MHz. Whatever the reason, Apple had a 667 MHz member of the Digital Audio family. It retailed for US$2,799 and was not very popular. It was discontinued while the other four models remained current.

Approaching the Age of Leopard

The Digital Audio Power Macs were a nice step up from the earlier Sawtooth and Mystic models. In addition to a faster system bus and AGP 4x video, they also zoomed past the 500 MHz mark. Graphics professionals who found the earlier 500 MHz models a bottleneck could get almost 50% more performance from the 733 MHz Power Mac G4.

All five of these models support CPU upgrades, both single- and dual-processor ones, so they can do a lot of heavy lifting with a brain transplant. Several vendors have dual 1.8 GHz upgrades available.

These Macs have a few hardware limitations, but less than earlier G4 Power Macs: They "only" support up to 1.5 GB of RAM ($125 at current prices), and the built-in Ultra ATA/66 drive bus is limited to a maximum hard drive size of 128 GB without the use of special drivers or adding a third-party ATA/100 or better PCI card.

These haven't been obstacles to running Mac OS X well on these machines, and they should be adequate for running Leopard. Even if Apple doesn't support installing Leopard, someone is bound to hack the installer.

With the right AGP video card, you could have full Core Image support, and if you're willing to "flash" the Windows version of the Sapphire Radeon 9600, which you can buy refurbished for $27 on eBay.

Bear in mind that it's not easy to find Mac video cards. One workaround is to flash the ROMs in a Radeon or GeForce card intended for Windows PCs, and The Mac Elite is a great resource for people who want to do that. They also have an article that explains how to get some AGP 8x cards working in older G4 Power Macs with nonstandard AGP sockets.

Closing Thoughts

We're Low End Mac, and although we're disappointed that it appears that all G3 Macs and a lot of G4 Macs are not going to be supported by Leopard, we think that the Digital Audio Power Macs could be competent Leopard machines.

Still, we suspect that Tiger will be the superior operating system on this hardware. But for those serious about running Leopard older G4 Power Macs, these could be good starting points. We recommend dual processors, lots of RAM, a fast hard drive, and an AGP video card that supports Core Image.

UPDATE: We have received numerous reports of Mac OS X 10.5 running on Digital Audio Power Macs, and we have lots of tips in our article on Unsupported Leopard Installation. 

Further Reading

• Low End Mac's best used Power Mac G4 deals, updated biweekly.
• How big a hard drive can I put in my iMac, eMac, or Power Mac?
• Guide to Power Mac G4 Upgrades for Power Mac G4 with AGP Graphics
• Make AGP 8x video cards work in G4 Power Macs, The Mac Elite. Instructions for disabling pins 3 and 11 so Mac compatible AGP 8x video cards will work in most G4 Power Macs.