Technology

Apple's Dual-Processor Mac G4


Despite their best attempts to convince consumers that CPU clock speed doesn't matter, Apple Computer and Advanced Micro Devices are both fighting a megahertz marketing gap. Industry titan Intel leads the numbers game with its Pentium 4 processor, which operates at 2 GHz, while AMD's Athlon trails at 1.6 GHz. Apple musters only 867 MHz with its best PowerPC G4, but the Mac maker is trying to compensate for the perceived power difference by offering a Power Mac with two 800-MHz processors. Unfortunately, we found that in most instances, the second processor remains tied behind the PowerMac's back.

We tried out Apple's top-of-the-line preconfigured system: dual 800-MHz processors, plus 256MB of RAM, an 80GB hard drive, and a DVD-Recordable drive, which, in addition to creating and DVD movies, also burns and reads CD-RW and CD-R discs. We tested that same drive for our last PowerMac review. (If you don't need the DVD-writing capability, you can get the G4 with a 12X/10X/32X CD-RW drive and save $400.) The system also provides 1000Base-T network support and a V.90 modem. The $3499 base price does not include a monitor, speakers, or an office suite, and relies on a 64MB GeForce2 MX TwinView graphics card, a low-end card on the Windows PC side; a GeForce3-based card costs $250 extra. The matching 17-inch LCD that came with our test system runs $999. You also can build to suit directly from Apple.

TWO BURNERS ON THE BOIL. Paying nearly $4500 for a screaming system could easily be justified by users for whom time is money, such as graphics professionals. But we found that while this is certainly one fast Mac, it's not a huge leap over the last Apple system we tested, the PowerMac G4/733. Part of that's software-related: All Macs currently come with both Mac OS 9.2 and Mac OS X; on the former, only applications that have been specifically written to take advantage of multiple processors (for example, Adobe Photoshop and Apple's Final Cut Pro video editor) will see any speed increase, and you can count those on two hands and an extra toe. (See this page for a complete list of multiprocessor-aware applications.) Even then, not all operations within those applications will be sped up.

In contrast, Mac OS X, Apple's newest operating system, supports multithreading (whereby a processor can handle multiple operations at the same time) and multiprocessing (in which the operating system can divvy up tasks among multiple processors); as a result, all operations should show at least a minor speed increase, but again, applications must be written to take advantage of multiprocessing to see a major benefit. Further complicating matters is that few major applications have been updated to run natively on OS X yet, though Microsoft says it will release Office v. X for Mac later this month.

We used Adobe Photoshop 6.1, one of the few applications that takes advantage of multiprocessing on OS 9.2, to gauge the PowerMac's speed. Photoshop hasn't yet been updated for OS X (but it will run via emulation within the new OS). We also tried out Corel's Painter 7, which runs natively under OS 9.2 and OS X.

We used both applications in informal tests with OS X 10.04 and the most recent version, OS X 10.1, to see if the update improved performance, as Apple claims. Good news for Mac fans: OS X 10.1 substantially speeds up application functions and system responsiveness over 10.04, though even our high-end Mac still doesn't seem nearly as responsive as it does under 9.2.

Rotating a 100MB image by an arbitrary angle (23 degrees) took 22 seconds in OS 9.2 with multiprocessing support enabled, and 28 seconds with it disabled. The same operation while running Photoshop under Mac OS X 10.04 took 47 seconds--more than twice as long as the best showing with OS 9.2--but it took only 25 seconds under OS 10.1. True, those times are slower than with the older OS, but Adobe will likely address the speed issue when it updates Photoshop for OS X.

Our tests with Painter 7 were less conclusive. Under OS 9.2, Painter isn't multiprocessor-enabled; nevertheless, the application ran much more quickly under 9.2 than OS X 10.04 or OS X 10.1. Corel confirmed that the application performs better under the older OS, but says it will release an update that will allow the application to take advantage of 10.1's performance enhancements before the end of the year.

Our overall impression is that, at this point, the second processor is of very limited utility. If you choose to run OS 9.2, the second processor provides only a minor speed boost in a few applications. If you run OS X 10.1, you may benefit from a tiny boost that the operating system gets from two processors, but you'll still have to run most applications under emulation, thereby negating the benefit. Most users will get better performance from the less-expensive 867-MHz single-processor system.

ON THE CASE. The QuickSilver case used by our test system is a minor update of Apple's previous excellent design. On the exterior, easy-to-grasp handles make toting it easy; pull a ring-latch and the side swings down like a tailgate. The motherboard is attached to the side panel, so once the case is open, the components rest within easy reach. Our system came with four open PCI slots and four open drive bays, though you must use a screwdriver to install any upgrades. A new external speaker on the front of the case looks like a funky power button, and people who see it for the first time often want to poke their finger in there, which puts the speaker at risk. The speaker itself is only good for system sounds--music sounds terrible, with very weak volume.

In addition, the SuperDrive no longer offers an external eject button, so to retrieve discs, you must hit a keyboard button. While the system's booting, waking up, or otherwise occupied, the button doesn't cause immediate action, which prompted us to hit the button again. You know what happens: The drive spits out the disc, then pulls it back in before you can grab it.

All PowerMac G4s come with integrated networking and sound, and the modem uses a proprietary connection, so the four open PCI slots provide plenty of expandability. However, unlike older Macs, this one does not support audio in--a big negative for musicians who use Macs for mixing. Apple offers a Creative Labs Sound Blaster Live card ($139 extra) that will add audio-in (as well as 3D sound), but OS X doesn't support it, and Apple won't say if or when it will.

The 17-inch LCD Apple Studio Display flat-panel monitor works very well with either operating system. The 1280-by-1024 screen shimmers a bit when it first starts up and sometimes takes a few seconds to fully brighten after waking from sleep, but once it's ready to go, images and text look very sharp, and colors really pop. Its unique case, which supports the two-footed panel with a kickstand, does not allow vertical adjustment. The TwinView graphics card allows you to connect two monitors and tile their displays, but unless you purchase a special cable, only one of the monitors can be an Apple model, because those all use the proprietary Apple Display Connector and the TwinView card's second connector is a standard VGA port.

As we've seen with previous Macs, DVD movies skip badly during playback under Mac OS 9.2 if you attempt any other operation--even if you simply hover over a playback control. Movies play much more smoothly in OS X 10.1, though we still saw minor stuttering when we started up other applications (which the multithreaded OS should be able to handle).

UPSHOT: While still a star performer for editing and exporting video, the value of the second processor is dubious, and many of the extras you'd expect with such an expensive computer come a la carte. Unless you work extensively in a multiprocessor-enabled application, we recommend sticking with a single processor and stocking up on more RAM. By Alan Stafford, PC World.com


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