Power Mac G5 range
IntroductionApple's self-proclaimed Year of the Laptop has drifted into even sharper focus with the steady decline of the company's professional desktop systems. While the PowerBooks have been in ascendance, Power Mac sales dwindled as we waited, and waited and waited for Motorola to produce a PowerPC G4 that actually obeyed Moore's Law of regularly doubling chip speeds. Even Apple stopped banging on about how the Megahertz Myth meant that its top G4 blew away the top Intel chips. Motorola had let the air out of Apple's argument. Saviour IBM - for so long the low-end G3 chip manufacturer - has turned its high-end server POWER4 processor into a sizzling desktop chip, the PowerPC 970 that Apple dubs the G5. Once the pro-Mac AltiVec optimizations were added and the 64-bit chip had proved itself capable of working with today's 32-bit software applications, Apple could once more step into the professional arena with a processor that more than matches its Intel and AMD rivals. But Apple didn't just screw the G5 into the Power Mac G4's case. It has redesigned and re-engineered practically everything about the pro desktop to make it as lean and up-to-date as computationally possible. The Power Mac G5 is more than just a speed bump; it's a major revision. Up to spec
The insides of the Power Mac G4 look like a Soviet-era Box Brownie compared to the sleek components of the G5. For starters there's a lot less within the heat-dissipating aluminium walls. The streamlined innards are populated by a razor-sharp parts and ports. Everything from RAM to hard-disk has been modernized, and is linked with a high-bandwidth architecture. Little of the power of the G5 processor is wasted, with throughput maximized by a speedy frontside bus that is matched by a new super-fast memory controller. Everything is integrated with HyperTransport interconnects. Port and slot technologies are forward-thinking, too. Next-generation PCI-X slots are to be found on the 1.8GHz and dual-2GHz models (if you aren't a big expansion-card user, the 1.6GHz model's older PCI won't bother you); AGP 8X for the upgraded graphics-processing cards is on all. FireWire 800, USB 2.0, Gigabit Ethernet and AirPort Extreme feature, and Serial ATA storage is fast enough for pro video-editing needs. The RAM isn't just faster, you can now stock up to 8GB of the stuff on the top two models. Cable clutter is kept to a minimum, and swapping drives and memory doesn't even require a screwdriver. The inside of the Power Mac G5 is an anal-retentive's dream. While video display is entirely digital - via a choice of either ADC or DVI, Apple has included a DVI-to-VGA adaptor for CRTs and projectors. Audio capabilities are also to the max, with the addition of digital audio in and out ports for connecting decks and digital instruments as well as surround-sound systems. While nothing is future-proof, the high-bandwidth Power Mac G5 is admirably up to date, and so shouldn't need upgrading to use tomorrow's peripherals. Performance test results
Macworld Lab tested all three models, and found them be clearly faster than the previous generation of G4 Power Macs. The two single-processor models are generally as fast or faster than the top-of-the-line dual-processor 1.42GHz Power Mac G4, and the dual-processor 2GHz Power Mac G5 is clearly the reigning Mac speed king by a wide margin. In Speedmark, our overall test of Mac system performance, the dual-2GHz G5 scored 258 (32 per cent faster than the previous fastest Mac: the 1.42GHz dual-processor G4, which scored 196), with the 1.8GHz G5 at 225 (15 per cent faster than the old top), and the 1.6GHz model at 207 (6 per cent). Clearly, from an overall-performance point of view, owners of recent Power Macs should skip the single-chip G5s for the dual-2GHz model, as it muscles in as a third as fast again as the previous speed champ. That's enough of a boost to persuade anyone that the G5 is the way to go for sheer brute force. But the Power Mac G5 really turns on the lights when it comes to professional-design applications, such as Adobe Photoshop and Maxon Cinema 4D XL. As previously, the real speed boost here is seen in the multiprocessor systems. The dual-2GHz G5 swept through our suite of Photoshop tasks in nearly a third of the time that it took a single-1GHz G4 Power Mac - if that jump in processing speed isn't worth an upgrade, I don't know what is. It's just under twice as fast as the dual-1.42GHz G4 - proving the G5's edge over the G4. When applications are optimized for the PowerPC G5's 64-bit architecture, these speed differentials should go through the roof. Adobe has already tweaked Photoshop 7.0.1 to grab some of the G5's so-far hidden speed. You'll need to download and install the free G5 Processor Plug-in update for Mac OS X, which modifies many Photoshop operations to fully utilize the G5 processor capabilities, and replaces the Adobe Color Engine component (ACECarbonLib) with a new version designed for the G5. In Cinema 4D XL, an application that takes full advantage of the G4's multiple processors, the G4 fared better than the 1.8GHz G5 model - but both were clearly blown away by the dual-processor G5, which was twice as fast as the dual-1.42GHz G4. In an interesting quirk, we found some dramatic speed differences in these systems depending on how we set the new Processor Performance preference, found in the Energy Saver pane of System Preferences. By default, Processor Performance is set to Automatic. Changing the setting to Highest improved our results quite a bit. Our MPEG-2 compression test, which took 9:44 on the 1.8GHz system at the stock setting, took 8:32 at the Highest setting. Overall Speedmark scores on the 1.8GHz system rose from 214 to 225 when we switched from Auto to Best. Another figure that jumps out of the Macworld Lab speed chart is the Dual-2GHz G5 Power Mac's Quake III frame-rate score, which is twice that of the previous top-end G4 Mac. A lot of the praise can be heaped on the 64MB ATI Radeon 9600 Pro video card, but some must be reserved for the Power Mac's much-improved internal architecture, as described earlier. The greater grunt of the G5 doesn't help all of our daily tasks, however. iMovie render times are barely distinguishable between the G5s and the dual-1.42GHz G4, for example. However, G5 users are more likely to be operating Final Cut Pro than iMovie, and the top-end G5 acquits itself well in the professional encoding stakes. Quiet revolution
Certain models of the Power Mac G4 behaved like underfed babies that needed changing. The new desktops should be even louder as the internals run so fast that Apple has had to fit each case with nine fans to keep everything bearably cool. Amazingly, the shush factor is minimal - thanks to some smart engineering that monitors temperature and dynamically adjusts fan speeds. Apple has made it easier to connect your favourite devices to the Power Mac by moving the most-used ports to the front of the case. Now there's no need to reach round the back when you want to link-up a FireWire or USB peripheral, or whack your headphones in to get some iTunes privacy. It's neat little touches like these that make you appreciate the Power Mac G5 inside and out. We can argue about aesthetics, but its harder to fault the practical design.