Power Mac G5 is Apple’s best work yet

Cupertino’s 64-bit desktop system and Panther OS mix beauty and exceptional performance

See correction at end of article

Companies large and small routinely set their expectations of computer systems according the capabilities of Intel-based x86 computers and 32-bit Windows. We’re due for a shift in standards.

Enter Apple, which got the bright idea of taking a pair of 64-bit IBM PowerPC CPUs, jacking them into server-class internal buses, and squeezing the whole thing into a desk-side tower chassis. The result, the Power Mac G5, delivers on the present need for rapid computing, deep multitasking, and responsive user interfaces — as well as the future need (current for some, including myself) for mainstream computers that rapidly process and analyze massive data sets.

If you’re on the edge of your seat waiting for a characterization of the Power Mac G5’s performance, here it is: Comparing official Standard Performance Evaluation Corporation (SPEC) dual-processor throughput tests with the unofficial numbers on Apple’s Web site, the 3.06GHz Xeon bests the 2GHz Power Mac G5 by some margin.

But wait, doesn’t Apple call the Power Mac G5 the world’s fastest PC? Yes, and I think that characterization was a big mistake from the beginning. The x86 architecture has the Intel compiler suite on its side. The Intel compilers are used to create most commercial and performance-sensitive applications for x86 software running on Windows and Linux. Apple won’t beat it until IBM gets serious about an architecture-tuned compiler for OS X.

Apple’s marketing choices aside, I believe that I/O throughput, especially memory performance, is infinitely more important than raw computing speed. Using the University of Virginia’s Stream memory bandwidth benchmark, the Power Mac G5 moves data almost twice as fast as a dual-processor 3.06GHz Xeon system: 2.2GB per second versus 1.3GB per second. (By way of comparison, memory throughput on a 17-inch PowerBook is 535MB per second.) I’m not cutting Apple special slack. Solid processing power and maximum bandwidth rule the day, and the Power Mac G5 has that combination down.

In a dual-processor Power Mac G5, the cost of talking to peripherals is also reduced substantially by the machine’s efficient and highly integrated system chip set. With the Power Mac G5, the penalty for accessing data that’s not in the CPU cache is reduced to a degree not possible with Xeon.

The Power Mac G5 takes the throughput flag, and it’s got something else you can’t get on the Xeon: the Panther OS (aka OS X 10.3). The client version firms Apple’s lead in graphics, boosting the performance of overall rendering and dramatically improving the display speed of PDF files. Panther server tightens links to Windows and Unix networks; reworks its directory services around open standards and a high-speed database; and adds a unified management interface that controls, among many other things, the new mail server, a Microsoft-compatible VPN, and streaming video services. As has long been true, the Mac is the platform to beat for client Java. Panther Server includes the open-source JBoss J2EE application server, complete with graphical administration and monitoring. The Panther client is beautiful and practical, while the server is powerful and painless.

The timing of this review bears explaining. Apple rushed the Power Mac G5 out the door in the fall of 2003 in order to win the race to be the first 64-bit desktop (AMD was in the other lane). The system’s delivery preceded the availability of the Panther OS, so the machine’s 64-bit capabilities could not be immediately exploited. Then there were no applications tuned specifically for the Power Mac G5, except for a preview of Photoshop. I did what I’d have done as a buyer of the Power Mac G5 and Panther: I waited until the platform came together and came to rest.

By mid-December, when this review was written, things had settled down. The Panther operating system had just received its second major update, 10.3.2. Apple had also updated the Xcode development tool set, upgraded the Power Mac G5’s firmware, and delivered QuickTime 6.5. In addition, the vital Fink project adapted its gigantic database of open source applications to make them compatible with Panther.

Bill of Particulars

Apple’s latest Mac is housed in an all-aluminum chassis, similar in size and weight to its predecessor, the Power Mac G4. In its maximum configuration (which I reviewed), the Power Mac G5 is driven by a pair of 64-bit IBM PowerPC 970 CPUs running at 2GHz. The list of external I/O ports is lengthy, but the highlights are FireWire, USB, Bluetooth, Gigabit Ethernet, AirPort Extreme (802.11g), and digital and analog audio. The Power Mac G5 holds up to 8GB of 400MHz DDR (double data rate) memory with a maximum transfer rate of 6.4GB per second. This configuration provides three PCI-X slots, which are all available. The optical drive in the top configuration is a Sony dual-format DVD burner. The two DVD formats are DVD-R/DVD-RW and DVD+R/DVD+RW.

The Power Mac G5 line has a starting price of $1,799. Memory capacity, bus bandwidth, and CPU speed are sacrificed to make the bottom end of the Power Mac G5 family more affordable. A uniprocessor Power Mac G5 is a substantial and affordable step up from a single-processor Power Mac G4, but it will be harder to see the advantages of the 64-bit architecture until more tuned applications appear. Dual-processor machines show an immediate benefit because the bus between the processors is extremely fast.

Panther client and server run existing 32-bit OS X applications, as well as most software written for Classic Mac OS. The Classic environment is hosted under OS X; the Power Mac G5 will not boot into Classic. Using the bundled Xcode development suite, any application can be recompiled to use the G5’s 64-bit features. The compilers are GNU’s, with PowerPC-specific contributions from IBM and Apple. In December, Apple made G5-tuned versions of its creative tools (DVD Studio Pro, Shake, and Final Cut Pro) available as free updates for existing users. The performance boost, especially for complex rendering, is substantial.

Inside the Box

The Power Mac G5’s chassis is filled mostly by fans of various sizes, along with the two humongous CPU heat sinks that are the Power Mac G5’s signature. There are nine fans in all, which the system controller rotates as slowly as possible to keep the noise down. The fans are arranged into independent cooling zones; air goes only where it’s needed. Next to the Power Mac G4 and every other single- and dual-processor machine in my lab, the G5 is virtually silent. Imposing a high load on both CPUs or the graphics card would spin the fans up, but never to the extent that the Power Mac G4 or the Xserve would.

The system is designed to be user-upgradable and user-serviceable. The system’s innards are concealed behind an easily-removed side panel. The Power Mac G5’s printed documentation describes, in plain language, how to add and remove system components. Apple recently instituted a program of supplying repair parts to customers as an alternative to site visits. The Power Mac G5 was clearly designed to support that approach.

Jaguar (OS X 10.2) Server was criticized for its shallow management interface, which forced administrators to resort to arcane methods to configure services by hand. The revamped management interface is much, much improved, although I wouldn’t judge it complete. All of the file-sharing settings and permissions should be combined into a single tab. Remote server management can only be done from another Panther machine; Jaguar is inexplicably not supported. The Panther Server management interface lacks a Web front end, too, which hurts because there is no efficient way to control the Mac GUI remotely.

For me, there is no administrative tool that compares to a terminal window. Apple finally addressed the thorny issue of Jaguar’s limited and poorly documented set of command-line tools. All of the OS X Server documentation has been reworked, and those docs are finally readable thanks to a retooled PDF engine that renders rich documents faster than you can scroll through them.

I was delighted that Apple replaced Jaguar’s clunky Sendmail SMTP server with the more respected Postfix. In practice, I don’t find Postfix to be an improvement, at least not the way Apple has implemented it. E-mail is one of the few services in Panther Server that was obviously cobbled together from open source parts. Keeping those parts loosely connected fits open source principles. However, this is one area where Apple can and should add unique value for mainstream customers.

The killer Panther Server feature is Windows interoperability. Panther will provide authentication, VPN, and file/print services to Windows clients, which creates interesting possibilities for reducing license costs.

The Ideal Mac

For the work I do, the Intel x86/Windows platform has fallen out of step with my requirements. I need my desktops to move and process multiple mountains of data, located in various places inside and outside the system, while maintaining a smooth, rich, and responsive user interface. I expect that from clients and servers. In the months I’ve worked with the Power Mac G5, I’ve found that the hardware, Panther OS, and the quite remarkable Xcode development environment form an ideal combination of usability and performance. It’s the ideal Mac; Intel’s Xeon simply can’t compete. If Apple wants a competing architecture to worry about, it should set its sights on Opteron. Apple should continue to make hay while Microsoft and Sun adapt their commercial operating systems to the AMD64 architecture.

I find digital media production to be a better overall predictor of compute and throughput performance than synthetic benchmarks, and in this regard, the Power Mac G5 stomps the Power Mac G4 and leaves the Xeon (running Adobe Premiere) choking on its dust. In the latter case, the Xeon system isn’t primarily hung up by a lack of compute power. The Xeon is hobbled by a shared bus that operates at half the speed of the fastest buses in the Power Mac G5.

Looking Beyond

I don’t want to look ahead too far, but the G5 architecture is going to make one hell of a server. That’s not conjecture. I ran all of my performance tests, including Final Cut Pro, on the Server edition of the Panther OS without bothering to shut down Panther’s services. I don’t care if cooling requirements will prevent Apple from squeezing a pair of G5s into a 1U rack chassis. I’ll generously set aside two rack spaces if I have to. My lab’s Xeon servers already occupy that.

I’m also jazzed about the possibilities of G5-equipped notebooks. It’s no accident that Apple paid such attention to Panther’s text and graphics rendering, with improvements in speed and quality most apparent in Panther’s handling of PDF and HTML. These set up innumerable possibilities for the rich, real-time presentation of complex and changing data.

Data analysis and translation, digital media, security, high-bandwidth data gathering, complex user interfaces, software development, and network monitoring are types of common applications that the Power Mac G5 handled sublimely in my tests. That describes the kind of work I do every day, a breadth of activity that colors my opinion of this system.

More than anything else, the Power Mac G5 shatters the long-standing limits of expectation imposed by Intel and Microsoft. Maybe you’re not a customer for this machine, but very shortly you will see shades of the Power Mac G5 in every dual-processor desktop you buy. The risk that Apple takes here is the same one it took with the PowerBook G4, OS X, Xserve, and Xserve RAID. Maybe customers aren’t as dull, as timid, or as easily led as other vendors believe.


In this article, a dual-processor 3.06GHz Xeon system's I/O throughput -- in the comparison with the Power Mac G5's -- should have been noted as 1.3GB per second. It has been corrected in this article.

InfoWorld Scorecard
Performance (20.0%)
Ease of use (20.0%)
Connectivity (20.0%)
Serviceability (15.0%)
Expandability (15.0%)
Value (10.0%)
Overall Score (100%)
Power Mac G5 7.0 10.0 10.0 9.0 8.0 8.0 8.8
Mac OS X 10.3 (Panther) 9.0 9.0 9.0 10.0 9.0 10.0 9.2
Mac OS X 10.3 (Panther) Server 9.0 9.0 10.0 9.0 8.0 10.0 10.0 9.3

Copyright © 2003 IDG Communications, Inc.

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