PowerBook G4 15in 1.5GHz review

Apple has a tough job on its hands persuading customers to buy one of its recently launched PowerBooks.

Whether you're thinking of buying your first portable Mac or are upgrading an older PowerBook or iBook, the chances are you're holding onto your credit card in anticipation of G5-based laptops. You could be waiting a while. Apple is still having difficulty fitting the red-hot G5 chip into a laptop along with all the necessary cooling devices.

With that in mind, it has refreshed the PowerBook G4 line with five new machines that run faster, have new features and cost less. In fact, new features are more significant in this release than raw performance improvement. True, the processor speed has increased from 1.33GHz to 1.5GHz, and up from 1.5GHz to 1.67GHz, but these are relatively modest improvements. The model we tested, the 1.5GHz 15in Combo, predictably performed almost identically to its 1.5GHz predecessor in our Photoshop test - our best measure of real-world performance - although it did perform better in the FileMaker test.

There are other enhancements that contribute to better performance in other areas, but its headline additions such as the new scrolling trackpad that are likely to catch potential buyers' imaginations. This patent-pending technology is, like many of Apple's inventions, a slick implementation of a very simple idea. Many PC laptops already feature dedicated areas to the side of the main trackpad that can be used to scroll vertically and horizontally through long or wide documents, but Apple's implementation is, in theory, much more elegant. You simply use two fingers anywhere on the trackpad instead of one, and this allows you to scroll through the window in which the pointer currently resides. It works well in practice, but we were disappointed that it was only partially able to pan around, say, a large image.

There are two reasons for this. First, a trackpad is small relative to any PowerBook's screen, so you rapidly run out of room. More importantly, though, because this technology appears to be designed primarily to facilitate scrolling through text-based documents and Finder windows, it tries to 'snap' to straight vertical or horizontal planes. Ordinarily, this is exactly what you want, as you don't want to have to try to move your fingers in a perfectly straight line when scrolling, but it has the effect of making any attempts to pan smoothly around an image coarse and jerky.

On a more positive note, it made no difference how closely spaced your fingers are for the scrolling to activate, so users with less nimble fingers should be able to use this technology.

Apple's other major announcement in the refreshed PowerBook range is the new Sudden Motion Sensor (SMS) technology designed to help protect the contents of your hard disk in the event of a fall or drop. When the PowerBook detects a sharp motion in any one direction, it immediately parks the read-write heads to avoid them crashing into the delicate surface of the hard disk's platters.

The circuitry that controls this is built into the motherboard rather than integrated into the hard disk, so Apple has the freedom to use hard disks from a range of manufacturers, and you can, in theory, replace the hard disk with another. Windows laptops from companies such as IBM and HP have featured similar technologies for some time, so it's good to see Apple finally incorporate SMS into its range, and we look forward to it filtering down to the iBooks and iPods.