Apple takes Power Mac G5 up a notch

The hardware just keeps on coming. Last week, Apple Computer showed off its latest shiny toys: new Power Mac G5 desktop computers with a huge leap in processing and graphics power at the high end. The more modest towers had a nice bump, too, along with some improvements to the PowerBook G4 series.

Apple also introduced a professional photographer's dream software package called Aperture, which we'll write more about after testing.

Power Mac G5s: The Power Mac line has a long history of frequent speeds bumps in which Apple upgrades a processor, a system bus (which handles communication between a computer's components) and memory speed. Most of these increases are modest.

But the latest Power Mac G5 models feature the first use in Apple's history of a dual-core processor. The dual-core idea is simple: Because it's difficult to create circuit boards that contain many processors, chipmakers have turned to embedding the equivalent of multiple processors in a single CPU (central processing unit).

A technique known as symmetrical multiprocessing allows programs and system activities that are properly designed to split their computational tasks across several separate units that operate in parallel. The more processors, the faster some tasks occur.

For most graphics and video processors, increased processor cycles produce faster results, because resizing an image or rendering a three-dimensional scene includes many calculations that can occur without being dependent on one another.

The improvement isn't perfectly linear, but it's still incremental. Apple's published benchmarks show that their top-of-the-line Quad — a dual-core, dual 2.5 gigahertz (GHz) Power Mac G5 — performs common graphics and video operations from 40 percent to 69 percent faster than its previous fastest machine, a dual 2.7 GHz G5 system.

The plain math is that 2.7 GHz times 2 equals 5.4 GHz; 2.5 GHz times 2 times 2 equals 10.0 GHz. The raw increase is 85 percent more cycles, but there's always some overhead for multiprocessing, and some activities that can't be split into pieces.

The new lineup comprises three systems, each of which has dual-core processors: the Dual 2 GHz ($1,999), Dual 2.3 GHz ($2,499) and Quad 2.5 GHz ($3,299). (Apple messed up and gave their models recognizable names, a rarity.)

All three models include a graphics card — occupying one internal card slot — that can support displays up to Apple's massive 30-inch Apple Cinema Display; the two higher-end models have twice as much video memory as the Dual 2 GHz.

But here's the scary part: With the new PCI Express expansion architecture built into the latest G5 series, you can install up to four graphics cards, each of which can handle not one, but two 23-inch LCDs. That's right: a single computer could drive eight large monitors. Sadly, you can only drive a total of four 30-inch Apple Cinema Displays due to their dual-DVI connector requirements.

The PCI Express slots also can more realistically drive custom digital signal-processing cards used to speed up graphics and video processing even further.

The Power Macs come with 512 MB of RAM, 160 GB (Dual 2 GHz only) or 250 GB drives, and a 16x SuperDrive. AirPort and Bluetooth are add-ons.

These dual-core processors come from IBM, which will supply desktop processors to Apple until the 2007 model year, when Apple plans to switch to Intel CPUs. IBM and Intel, among other chipmakers, expect dual-core processors as just a start, with quad core and even nine-core processors in the pipeline.

Processor followers might note that IBM's single-core G5 chips ran faster than these dual cores. Apple's dissatisfaction with IBM reportedly was linked to processor-speed improvements that even multiple cores couldn't allay.

PowerBook G4s: The latest refresh of the Apple PowerBook G4 series has gotten denser, but I'm not referring to its weight. Rather, the 15-inch and 17-inch models have boosted the number of pixels in the same space as the computers they replaced.

It's been years since the basic pitch, or numbers of pixels per inch, of laptop LCDs has improved significantly. The greater the pitch, the more detail you can see, and the more realistic images look on a screen.

The 15-inch PowerBook G4 had its overall resolution increased from 1152 x 768 pixels to 1440 x 960, or a 56 percent leap in total pixels. The 17-inch model was 1440 x 900, and now measures 1680 x 1050, or a 36 percent increase.

Apple improved the series' audio and eked out about 20 percent more battery life as well on the 15-inch and 17-inch models.

Apple simplified its model line to just a single processor configuration for each size. The 12-inch ($1,499) runs at 1.5 GHz; the 15-inch ($1,999) and 17-inch ($2,499) now sport 1.67-GHz processors. The SuperDrive is standard on all models, but can be downgraded to a Combo Drive (no DVD writing) for a $50 savings.

Glenn Fleishman writes the Practical Mac column for Personal Technology and about technology in general for The Seattle Times and other publications. Send questions to gfleishman@seattletimes.com. More columns at www.seattletimes.com/columnists