Product Reviews

This is the first time that Apple's professional range of Macs has entirely consisted of dual processors. There are two main reasons for this: Mac OS X is able to take advantage of multiple processors at a system level and Motorola is unable to develop processors with a significantly higher clock speed in the time frame that Apple needed to update its machines.

Professional Mac users have had a rough ride over the last 12 months. While consumers have been enticed by a brand new iMac and the launch of the eMac, there's been precious little to persuade high-end users to part with their cash. Even the release of dual-processor 1GHz Power Macs in January caused barely a ripple of excitement among professionals. So there was a great deal of hopeful speculation after Apple announced there would be a new crop of professional machines.

How fast would they be? What processor would they use? Would they feature 800Mbits/sec FireWire and USB 2.0? For those trying to answer these questions, the way in which Apple announced the machines gave some indication. There was no Jobs keynote address, no special event, just a few press releases slipped out on a quiet Tuesday in August, perhaps showing that Apple was not overly impressed with the specifications of its new machines. In fact, only the fastest of the three new machines features a clock speed quicker than the current range of Power Macs, albeit that this is a speed increase of 25%.

On the plus side, all three new machines feature a redesigned case and the top two models, 1GHz DP and 1.25GHz DP machines, have a new motherboard. This is based on the Xserve architecture, which has a faster, 167MHz system bus and support for double data rate (DDR) RAM - both of which should mean faster throughput of data. The low-end 867MHz DP machine, also has support for DDR SDRAM.

Casing the joint

The case had to be redesigned to accommodate the four cooling vents on the front of the Power Macs. The extreme heat generated by G4 processors running at faster clock speeds meant that the Quicksilver design of the previous Power Mac G4s would not have provided adequate cooling for the 1.25GHz dual processors.

The speaker has moved to the top of the Power Mac's case with the power button situated below it. There's no restart button, hard restarts are now achieved by holding down the power button. Alongside the power switch, on the new chrome-effect drive bay fascia, is a headphone mini-jack - the first time Apple has put a headphone socket on the front of a professional machine.

The second drive bay now supports another optical drive. This is perhaps an admission that the CD reading and writing speed of the SuperDrive is so far behind the leading edge that many professional users will want a dedicated CD writer. However, only the DVD-ROM/CD-RW combo drive is offered as a build-to-order option and this has a maximum CD writing speed of 16x, about half the speed of new CD writers.

Round the back of the new cases, the plastic has been punctured with as many holes as could be made without it falling apart - again for cooling reasons. The change in motherboard means that the four PCI slots now sit near the top of the case, while the expansion ports have been moved from top to bottom, still on the left.

The internal changes are more dramatic, most notably the enormous increase in size of the heatsink that now covers the processors. Other aids to cooling include a larger fan, situated below the optical drive bays, and a second fan next to the motherboard.

The new system architecture on the two higher-end machines has a system bus speed of 167MHz, compared with 133MHz on the 867MHz Power Mac. The Level 3 cache on the 867MHz and 1GHz machines is 1Mb a processor and 2Mb a processor on the fastest machine. The bottom two machines both ship with 256Mb RAM, while the 1.25GHz boasts 512Mb. The top two Power Macs support PC2700 SDRAM, which has a faster throughput than the PC2100 supported on the 867MHz. There is a maximum 2Gb RAM on all three machines.

The new machines ship with 7200rpm Ultra ATA/100 hard drives - 60Gb, 80Gb and 120Gb respectively. There's room on the ATA/100 bus for one more drive, and there's also an ATA/66 bus with room for two hard drives. So you can have up to four hard drives inside one Power Mac. If you need faster throughput than ATA/100

Graphics support is provided by a Nvidia GeForce4 MX with 32Mb DDR SDRAM on the 867MHz machine, and by an ATI Radeon 9000 with 64Mb DDR SDRAM on the other two machines. There's also a build-to-order option to replace the standard graphics card with a Nvidia GeForce4 Ti with 128Mb DDR SDRAM.

Points of entry

The rest of the specifications are unchanged, they have Gigabit Ethernet, an AirPort antennae, a 56K V.92 modem, two 400Mbits/sec FireWire ports, two USB ports (as well as the two on the keyboard), stereo audio line-in and line-out on the rear (in addition to the headphone jack on the front) and an Apple Pro Speaker jack.

All the new Macs come preinstalled with the latest operating system, Mac OS X 10.2. The OS X installation includes Apple's new instant messaging client, iChat, as well as the new Address Book and Mail applications. However, iCal and iSync won't be available until the autumn. Mac OS 9.2 is also preinstalled so you can choose to boot into it or use Classic. Other software includes Apple's suite of iApps - iMovie, iTunes, iPhoto and iDVD (on the SuperDrive models), plus Snapz Pro, OmniGraffle and OmniOutliner, a trial copy of FileMaker Pro and Apple's Developer Tools CD.

Testing times

So much for the specifications, but how do the new Macs perform? The 1.25GHz won't be available until the autumn and there were no 1GHz machines in the UK when we went to press. However, we did manage to test the 867MHz DP using MacUser's benchmark suite.

There's a great deal in the specifications to suggest that the machines should perform significantly better than the equivalent machines in the previous line-up, especially as there are dual processors on every Mac, DDR SDRAM, a faster system bus on the 1GHz and 1.25GHz models, as well as better graphics systems. We particularly expected to see a big jump in the performance during our Photoshop and Cinebench tests, which are multiprocessor aware.

We compared the test results from the new 867MHz DP with a year-old single-processor 867MHz fitted with a GeForce2 MX video card. While the Cinebench showed a significant improvement with the time taken to do a test render, dropping from 17 to eight seconds, the time taken to complete our Photoshop Actions test was only 14.5% less, going down from 117 to 100 seconds. These are hardly earth-shattering results.

In our Quake III Arena frame rate test, the 867MHz DP with its GeForce4 MX managed to improve on the performance of the single-processor 867MHz with its GeForce2 MX by only one frame a second, or around 1.5%. And our FileMaker Pro-based test consisting of a series of processor intensive operations confirmed the performance similarity. Running one non-multiprocessor aware application at a time, we wouldn't expect the dual processor to make any real difference to performance, but we had thought that the faster memory might have given it a boost. It seems that this isn't the case.

Benchmark tests of the CPU and FPU throughputs also gave results that were too close to call. Although we haven't tested the 1GHz model yet, anecdotal evidence circulating on the Web suggests that users who have compared the new 1GHz with the 1GHz launched in January found no improvement.

The benefits of having two processors will be seen by OS X users running more than one application or task at a time. OS X's pre-emptive multitasking and multithreaded Finder allow these tasks to be handled by different processors. So although our individual tests show little performance improvement, in everyday work the ability to let one processor handle a task while you get on with something else is likely to enhance productivity. And if you do use multiprocessor aware applications, such as Photoshop or Cinema 4D, on a regular basis, you'll see benefits when running in OS 9 or OS X.

It's possible that the DDR SDRAM, and, if the anecdotal evidence is accurate, the faster system bus, won't have much effect on performance because the bottleneck is in the processor itself. When the next generation of G4 chip, the 7457, is employed in Power Macs, we may begin to realise the true benefits of the revised motherboard.

In summary

At first glance, the specifications of the 867MHz DP are uninspiring, and a look at the test results bears this out. However, it's not all doom and gloom. There's plenty to be positive about the specification of the low-end Power Mac- it has a maximum 2Gb RAM, an additional optical drive bay, an extra internal hard drive bay and, effectively, two processors for the price of one.

Equally, there's no doubt that the slow progress on PowerPC development is holding back the Power Mac range. If you already have a Quicksilver G4, there's little reason to upgrade. But if you own an older Power Mac, the 867MHz DP will give you a performance boost for an excellent price.