Second-Generation Power Mac G5

Back in June 2003, when Apple announced its first Power Mac G5 models, performance-hungry pro users heaved a sigh of relief. Compared with the G4 line, the new machines offered an elegant enclosure, a sophisticated cooling system that didn’t make a racket, and lots of other state-of-the-art technology.

Above all, there was the PowerPC G5 processor. Besides a huge one-time performance boost, it was supposed to provide plenty of headroom for future advances, thanks to a streamlined architecture and a manufacturer—IBM—renowned for its chip-building prowess. The lagging performance and frustrating delays that marked the Motorola-built G4s were ancient history, we were told at the WWDC. Steve Jobs even promised an assemblage of Apple developers last year that the top of the Power Mac line would hit 3GHz—a 50 percent speedup—by mid-2004. Unfortunately, things haven’t quite worked out that way. Just like Intel and other chip makers, IBM ran into unexpected difficulties as it moved to a new generation of production technology. For a year the G5 stalled at a maximum speed of 2GHz, and when Apple announced new Power Macs in June of this year, the best it could offer was 2.5GHz—embarrassingly short of Jobs’s promise. And IBM even had trouble living up to that commitment: the new high-end Power Mac, with dual-2.5GHz G5 processors (that is, two completely separate chips, not one chip with dual processing cores) was supposed to ship in July, according to Apple’s announcement, but didn’t actually begin to reach impatient customers until late August.

Still, the new model is finally here, along with new versions of its dual-2GHz and dual-1.8GHz siblings, and it delivers a substantial, if not earthshaking, speedup. The improvement is noticeable even in mundane tasks like unstuffing files, scrolling through PDF documents, and browsing the Web, but as you’d expect, the benefits are most significant in demanding image- and multimedia-processing work (see the benchmark chart).

Three Times Two

As usual, Apple offers three standard Power Mac configurations, but now they all have dual processors. The top-of-the-line system is priced as before at $2,999, but it now comes with a pair of the new 2.5GHz G5 processors. The midrange, $2,499 configuration, formerly powered by dual-1.8GHz processors, now has two that run at 2GHz. And what used to be the least expensive Power Mac, with a single 1.6GHz G5 chip and a price tag of $1,799, has been replaced by a dual-1.8GHz model priced at $1,999.

All three configurations now have 8x SuperDrives, up from 4x in the previous generation. That advance hasn’t attracted a lot of attention, but if you burn many DVDs, you’ll definitely appreciate it. As before, 512MB of memory and a 160GB, 7,200-rpm Serial ATA hard drive are standard in the top-of-the-line and midrange models, while the entry-level configuration has only 256MB of RAM—barely adequate to run OS X—and an 80GB, 7,200-rpm hard drive.

Those aren’t the only ways in which the new dual-1.8GHz configuration resembles the discontinued solo 1.6GHz model—it also shares some inherent technological limitations. The logic boards, for example, have only four DIMM slots and are limited to a maximum of 4GB of RAM, compared with eight such slots and a maximum of 8GB of memory on the higher-end configurations. And while the expansion slots in the high-end models are based on PCI-X technology, those in the new dual-1.8GHz configuration handle only cards built for the older and slower PCI standard. Apple has marketed three different Power Mac G5s with 1.8GHz processors so far. Both the original single-processor model and the dual-processor version that replaced it had PCI-X slots and could handle 8GB of RAM; the latest version has PCI and a 4GB limit on memory. All of this could add up to a nightmare for system administrators in organizations with many Macs. It’s enough to make you pine for meaningful model numbers.

Of course, not everyone—not even every pro user—needs 8GB of RAM or PCI-X slots. In fact, 15 months after Apple announced its first PCI-X systems, the Made4Mac database of third-party products on the company’s Web site still showed only four Mac-compatible PCI-X cards. Still, it makes sense to give some hard thought to your future as well as present hardware needs before you shell out about $2,000 for a system Apple has deliberately hobbled.

Power Graphics

Like their predecessors, all three new machines have an AGP (Advanced Graphics Port) 8X Pro slot. Nvidia’s GeForce FX 5200 Ultra, with 64MB of dedicated memory, again fills it on the standard entry-level and mid-range configurations, while the high-end system now comes with the 128MB ATI Radeon 9600 XT, successor to the 9600 Pro that was standard in the old high-end setup.

If you have your Power Mac configured to order, you’re free to upgrade to higher-performance graphics: Buyers of the low-end and mid-range models can move up to the Radeon 9600 XT for $50 more, to the new ATI Radeon 9800 XT for $350, or to the Nvidia GeForce 6800 Ultra DDL (required if you’re going to use Apple’s new 30-inch Cinema HD display) for $500; from the high-end Power Mac, the upgrades are $50 less. (We tested only the standard cards.)

All of these cards support dual displays. The GeForce FX 5200 Ultra and the two ATI cards have one Apple Display Connector (ADC) port, for use with Apple’s recent flat-panel monitors, plus an industry-standard DVI port for older and non-Apple displays (including, via an adapter that’s included, standard VGA monitors). The optional top-of-the-line GeForce 6800 Ultra DDL lacks an ADC port; but has two DVI connectors.

A few words of warning to keep in mind as you’re choosing your video card: First, the two optional high-end cards–the ATI Radeon 9800 XT and the Nvidia GeForce 6800 Ultra DDL–are both so big that they block the adjacent PCI or PCI-X slot, reducing the number of usable expansion slots from three to two.

Second, some third-party displays may not work with the cards Apple offers. An AG Neovo flat-panel display we’ve used with Power Mac G4s wouldn’t work at all when connected to the Nvidia card in the new dual 2.0-GHz G5, though it worked fine with the Radeon 9600 XT in the high-end model. Posts in the discussion forums on Apple’s online support site report problems with displays from Samsung and several other manufacturers.

Any Port in a Storm

In other respects, the new Power Macs are basically similar to their predecessors. They have the same enormous enclosure with brushed-aluminum surfaces and a hole-punched grille on the outside, and an elaborate thermal-management system, with plastic baffles and nine fans, on the inside. In the high-end model, a water-cooling system built into the processor modules—and therefore invisible to the user, even when you remove the Power Mac’s side panel—helps keep the dual 2.5GHz processors from melting down. You’ll still hear the fans kick in fairly often, particularly when you’re doing processor-intensive work, but sometimes for no obvious reason. Like the original G5s, however, the new systems are noticeably quieter than Power Mac G4s.

In terms of connectivity, the new G5s sport the same rich variety of options as last year’s models. A USB 2.0 port, a FireWire 400 connector, and a headphone jack are conveniently located on the front panel. On the back there’s an even dozen ports: two for USB 2.0; one each for FireWire 800 and 400, Gigabit Ethernet, and the built-in 56-Kbps modem; four audio jacks (analog and optical in and out); and antenna connectors for optional internal AirPort Extreme and Bluetooth cards ($79 and $50, respectively).

The Price/Performance Equation

In the previous generation of Power Macs, the midrange model was the clear standout in terms of bang for the buck once Apple added a second 1.8GHz G5 processor. In the new lineup, however, the price/performance ratios look quite different. First of all, the high-end configuration, with its 2.5GHz processors, now holds a much larger speed lead—21 percent on our Photoshop test, for example—over the midrange model.

At the other end of the spectrum, now that the base configuration also has dual processors, it’s no longer the relative laggard the entry-level Power Mac used to be: on our Speedmark benchmark, the new dual-1.8GHz system trails the dual-2GHz model by only 8.5 percent; in the previous generation, the base model, with a single 1.6GHz G5 processor, came in almost 23 percent behind what was then the midrange configuration (with two 1.8GHz chips).

Macworld’s Buying Advice

For the graphics and media pros the Power Mac G5 line is designed for, we think the clear speed advantage of the dual-2.5GHz model makes it well worth its $2,999 price tag. But if your budget is tight, you can live with a little less than maximum performance, and you don’t foresee any need for PCI-X or more than 4GB of memory, then our recommendation is the $1,999 base model. It’s only a little slower than Apple’s midrange offering, and even after you add some RAM and maybe a larger hard drive, you’ll still save several hundred dollars.