November 24, 2003

Review: The new Power Macintosh G5

Author: Chris Gulker

Apple's new 64-bit Power Macintosh G5 is aptly named: it has power to burn. Mac and *NIX users who can afford these machines will find them to be much faster than the Power Mac G4s they replace and at least as fast as any PC you can buy or build today.

I tested a single-processor model; Apple this week announced that the single-processor 1.8 MHz machine was being replaced by a dual processor configuration. After five days in a quiet home office, the 1.8 GHz G5 still amazes me not only with its speed but its quietness. Even with eight fans in its large, heavily drilled aluminum case, the G5, barely a foot from my chair, can't be heard over the relatively quiet iMac that sits in a corner farther away. When my AMD Linux machine is on, the noise of its five fans swamps even the iMac.

Quiet functioning is just one feature of what appears to be a classic Apple-at-its-best engineering job. The G5 machine is big: 20.1 inches high, 8.1 inches wide, and 18.7 inches deep -- three inches taller than the previous plastic G4 tower. At almost 40 pounds, it's heavy too, and you quickly become grateful for the massive aluminum handles on all four corners of the box.


Front view -- click to enlarge

Unlike most of the PC boxes around here, the fit and finish of this machine are superb. A smooth lever releases the G5's heavy aluminum side panel to reveal a clear plastic air management baffle that segregates the G5's interior into zones served by the G5's fan arrays. All of the pieces lift off easily and go back intuitively when time comes to button up. Access to PCI slots, RAM, and the spare hard drive bay is much easier than typical PC layouts.

Overclockers will drool when they see the G5's cooling setup, which includes onboard temperature sensors, control circuitry, and software for the fans. The aluminum chassis and mesh front keep the machine cool enough that the fans normally turn slowly and silently. Interestingly, when you remove the clear air baffle with the power on, a red light comes on in the G5's case and all of the fans throttle up to full -- and sound a lot more like an Intel or AMD machine.

For all its size, the interior of the G5 has fewer, if faster, expansion options than its predecessors. The G5 has three PCI slots, versus four in the G4 towers, two hard drive bays versus four in the G4, and room for only a single optical drive versus two in the G4. The G5's IBM PowerPC 970 heatsink, fans, and baffles use up the rest of the space.

The G5 offers 64-bit PCI-X slots on its two fastest models, with one running at 133MHz and the other two at 100MHz, while the entry-level 1.6GHz machine offers three slower 33MHz PCI slots. The G5 has two 150MHz serial ATA controllers, up from the 100MHz Ultra ATA controllers in the G4, and ships with one 80GB (1.6 GHz machine) or 160GB 7200RPM drive. While the serial ATA connectors are much smaller and easier to connect than the fat ribbon cables found in the older machines, the lack of a legacy ATA bus means older ATA drives can't be used in the G5 without adding a PCI card, and the G5's case layout would make that, at best, a tricky proposition.

The G5 also has an AGP 8X graphics card slot that comes filled with either a Nvidia GeForce FX 5200 (1.6 and 1.8 GHz machines) or ATI Radeon 9600 Pro (dual 2GHz). Both cards support dual displays up to 1920x1200 pixels in either mirror or contiguous mode. You can hang acres of screen space on the ADC and DVI connectors. A DVI to VGA adaptor allows use with CRT displays, though at somewhat lower maximum resolution.

The Mac G5 offers either four or eight slots for PC2700 (333MHz) or PC3200 (400MHz) RAM in the entry level and faster machines respectively and supports up to 4GB or 8GB of RAM versus the G4's 2GB. Unlike the G4, the G5's 128-bit data paths can take full advantage of the DDR RAM with up to 6.4Gbps throughput.


Side view -- click to enlarge

The G5 still trails Intel in raw clock speed at a current 2GHz max, but the combination of 64-bit data paths and fast front side buses -- the 800MHz, 900MHz, or 1GHz buses are as much as six times faster than the G4 -- will at least make the "who's fastest?" discussions a lot more interesting than they have been in recent years, when Mac performance badly trailed Intel and AMD-based machines.

Apple has advertised the G5 as the "the world's fastest PC," but current marketing verbiage refers to "one of the fastest PCs ever built." Apple claims that the G5 smokes Pentium 4 and Xeon processors in any number of benchmarks and application tests.

An interesting set of tests was conducted by PC World, which proclaimed several AMD Athlon 64 and Opteron chips worthy competitors, if not downright winners, against the G5. (If anyone wants to send a 1.8 GHz Athlon 64 or Opteron system here for a subjective user comparison, feel free.)

Speed is precisely the user's impression: very large image files rotate almost instantly in Photoshop, particularly with the G5 plug-in installed. Applications launch in one "bounce" of the dock. Amazingly, 32-bit apps run much faster on the G5 than the G4, no doubt due to the board's massive bandwidth: I can hardly wait to see what 64-bit apps will do.

Some user-oriented features, long ignored by Apple, are welcome additions to the G5. The box has front-mounted USB 2.0 and FireWire 400 ports and an earphone jack, which should end the spectacle of Mac users prone under their desks trying to attach peripherals or use headphones. Curiously, the headphone jack cuts out the internal speaker, but not speakers connected to the machine's back panel line out jack. Audio and video types will be pleased to note that the analog line in and line out jacks are augmented with optical digital in and out jacks.

The G5's back panel holds twin USB 2.0 ports, FireWire 400 and 800 ports, and a 10/100/Gigabit Ethernet jack (though many complain that Apple's Gigabit Ethernet drivers still won't go much over 400Mbps). Surprisingly, the newly redesigned Apple keyboard's built-in USB hub supports only the 1.1 standard.

While Mac power users will see vast improvements in their power-hungry apps, *NIX users will appreciate the power, too. Apple's OS X 10.3 Panther OS rides on top of the FreeBSD-based Darwin 7.0, which features a 64-bit kernel and system math libraries updated to take advantage of the G5. Mac OS X 10.3's GCC 3.3.3 compiler appeared to compile source much faster than the GCC 3.2.2 compiler on my 1 GHz AMD machine, but comparing a two-year-old 32-bit PC to a G5 isn't really fair.

Apple's version of X11 runs faster on the G5 than on my G4 (X11 is now an optional install in Mac OS X), as do Aqua and Quartz Extreme, Apple's windowing and graphics systems. Users who prefer Linux should note that both Gentoo Linux and Terra Soft Solutions, distributors of Yellow Dog Linux, have announced releases of their distros for the G5.

Final verdict: this is a very fast, well-engineered, and well-built machine. Mac and *NIX users who can pony up the minimum $1,799 price for a G5 won't be disappointed with the speed or craftsmanship of this fine machine. Apple, often the innovation leader, is now a performance leader as well.

Chris Gulker, a Silicon Valley-based freelance technology writer, has authored more than 130 articles and columns since 1998. He shares an office with 7 computers that mostly work, an Australian Shepherd, and a small gray cat with an attitude.

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