New Power Mac G5s deliver speed

The latest update to the Power Mac G5 line is very much an evolutionary, rather than revolutionary, event. Apple made no changes to the design, core technologies, or the line’s price points. What it did deliver is faster processors, roomier hard drives, beefed-up video cards, and a new and improved double-layer SuperDrive.

Altogether, the changes are hardly startling, and they probably don’t justify a trade-up for most users who bought one of last year’s Power Macs. But for new buyers, the minor alterations add real value.

Although the long-awaited 3GHz G5 chip still lies somewhere beyond the horizon, the new $2,999 Power Mac G5 comes closest to it. This Power Mac’s two liquid-cooled G5 processors run at 2.7GHz, up from 2.5GHz in the previous top-of-the-line model (   ; December 2004 ). The midrange configuration, priced at $2,499, now has a pair of 2.3GHz CPUs, up from 2GHz, while the $1,999 base dual-processor system went from 1.8GHz to 2GHz per processor. With the faster CPUs, the frontside bus—the channel that connects the processors to the system memory controller—also gets a speedup, because in these machines it’s designed to run at half the speed of the CPUs.

(The one Power Mac unaffected by this update is the $1,499 entry-level model [   ; February 2005 ]: for the moment, it still has a single 1.8GHz G5 processor, fed by a bus that runs at one-third the speed of the CPU.)

The dual-processor models’ higher clock speeds translate to correspondingly better performance in the real-life applications that make up Macworld Lab’s new Speedmark 4 benchmark suite. Overall, the new machines are 11 to 15 percent faster than their predecessors. (See how they stack up in the Macworld Lab's benchmark tests ). For those who run the most demanding Mac applications, the seemingly modest increment can make a big difference. For example, Apple points out that the new dual-2.7GHz Mac, combined with the latest version of Final Cut Pro, is the first personal computer ever to permit simultaneous, real-time editing of two streams of uncompressed video.

One complexity to watch out for: while the old dual-2GHz Power Mac could accommodate as much as 8GB of RAM, the new one can hold only half as much; likewise, the new one’s three expansion slots are based on the PCI standard, not on the faster PCI-X technology found in the 2.3GHz and 2.7GHz systems (as well as last year’s 2GHz and 2.5GHz models). In these respects, the new 2GHz model more closely resembles its $1,999 predecessor, which had two 1.8GHz processors, than it does the previous dual-2GHz system.

Tons More Storage

All three updated models feature appreciably larger 7,200-rpm Serial ATA hard drives. In the $1,999 configuration, hard-drive capacity has doubled, from 80GB to 160GB; in the two other systems, it has jumped from 160GB to 250GB. Standard memory in the $1,999 system also doubled to 512MB, catching up with the pricier models.

All three dual-processor machines come with a new SuperDrive, which offers two advantages over the one in previous dual-processor Power Mac G5s. First, this SuperDrive can read most DVDs and burn standard DVD-R discs at 16x, twice its previous speed. Second, the new drive is the first from Apple that can burn double-layer recordable discs, which hold a whopping 8.5GB—a big jump from the 4.7GB capacity of single-layer DVD media. In concrete terms, double-layer discs hold as many as 3.5 hours of MPEG-2 video, compared with 2 hours on single-layer discs.

Anyone who uses optical media for backup or archiving will appreciate the extra capacity of double-layer DVDs, but the biggest beneficiaries are video editors working on long movies. Until now, if they wanted to send clients single-disc versions of big projects for a final look, they had two choices: send their work out to a service bureau or use non-Apple drives that aren’t directly compatible with Apple’s iDVD and DVD Studio Pro (see “Dual-Layer 16x DVD Burners,” April 2005 ). Now they can burn professional-scale projects directly from the Apple applications.

A few cautionary notes, though: First, DVD+R DL discs, the double-layer format the new SuperDrives require, are not cheap. At brick-and-mortar stores, packs of three typically go for about $20. You can find lower prices online, of course, especially if you buy in bulk, but don’t expect the kinds of bargains that are common for single-layer DVD media.

Second, don’t expect blazing speed. The new Power Mac SuperDrive has a maximum speed of 4x for double-layer burning, and even that—like all speed ratings on optical drives—isn’t a very good guide to real-life burn times. When we tried backing up 7.5GB of data from the Finder, it took 51 minutes and 37 seconds to complete the job, including verification.

Faster Bluetooth, Bigger Screens

Like their predecessors, the new Power Macs offer a wealth of network and peripheral connectors. 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 a dozen ports: two for USB 2.0; one each for FireWire 400, FireWire 800, Gigabit Ethernet, and an internal V.92 56-Kbps modem (now a $29 option); four audio jacks (both analog and optical inputs and outputs); and antenna connectors for optional internal AirPort Extreme and Bluetooth cards ($79 and $50, respectively, or $99 for both, if ordered at the time of purchase).

The only change here is that Apple’s Bluetooth card for the Power Macs now supports the latest standard, Bluetooth 2.0+Enhanced Data Rate (EDR). Aside from the latest PowerBooks, there still aren’t many Bluetooth 2.0 devices out there yet, but when they arrive, the new Power Mac card will be able to exchange data with them at three times the rate of older Bluetooth connections. The faster rate should translate into longer life for battery-powered devices and smoother performance if you have multiple Bluetooth devices connected at once. (For more on Bluetooth 2.0+EDR, see “Inside Bluetooth 2.0”.)

Apple has also updated the default video cards in all three dual-processor Power Macs. The $2,999 model, in which an ATI Radeon 9600 XT card with 128MB of video memory used to be standard, now has a Radeon 9650 card with 256MB of video RAM. In the other two models, the Radeon 9600 with 128MB of RAM is now standard, replacing the Nvidia GeForceFX 5200 Ultra with 64MB of memory.

We didn’t detect any particular performance benefits from the new cards—in fact, the dual-2.7GHz Power Mac with the Radeon 9650 card delivered fewer frames per second in our Unreal Tournament test than the old dual-2.5GHz model with the Radeon 9600 XT card. The main benefit of the new cards is that they provide painless support for larger screens—in particular, Apple’s 30-inch Apple Cinema HD display. Previously, none of the Power Macs, not even the top-of-the-line model, supported the 30-inch Cinema HD without a $450 or $500 upgrade to the Nvidia GeForce 6800 Ultra DDL, a card that also had the disadvantage of blocking one of the PCI or PCI-X expansion slots. You’ll still need that upgrade if you want to connect two 30-inch Apple monitors, but if you can scrape by with just one, the Radeon 9650 will do the trick at little or no extra cost. The Radeon 9600, the card that’s standard in the $1,999 and $2,499 systems, still can’t handle the 30-inch display—it’s limited to a paltry two 1,920-by-1,200-pixel displays, such as Apple’s 23-inch HD flat panels—but buyers of either of those models can upgrade to the Radeon 9650 for a mere $50.

One historical note: the new Power Macs mark the passing of the Apple Display Connector (ADC). All the video cards Apple offers with the new Power Macs feature two DVI connectors. If you want to hook up an older ADC-based display, you’ll need Apple’s DVI-to-ADC adapter ($99) or a third-party equivalent.

Macworld’s Buying Advice

All of these machines have strong merits and would be good choices for people in the market for a Power Mac. If you spend your days doing processor-intensive tasks on big files—whether it’s applying image filters, encoding video, or engineering genes—the dual-2.7GHz system may be worth its price. However, if you can live with less than maximum performance, the other two models offer more bang for the buck. The dual-2GHz model delivers 82 percent of the performance of the top-of-the-line model at two-thirds the price, but it lacks PCI-X slots and is limited to 4GB of RAM. If those limitations bother you, the dual-2.3GHz system may offer you the best balance of performance, technology, and cost.

[ Henry Norr is a former editor of MacWeek and a former technology columnist for the San Francisco Chronicle.]

Power Mac G5

Subscribe to the Apple @ Work Newsletter

Comments