iMac 2.8GHz review

This revamp of Apple's slimline all-in-one Mac keeps the same aluminium and glass exterior that was first unveiled last summer, but beneath the surface lies a major performance improvement.

In our tests, this 2.8GHz model beat the previous 2.4GHz iMac by around 50% in raw processing power. That's a huge increase, far beyond what the higher clock speed would suggest. If you want even more, there's a 3.06GHz option too.

The new iMac also comes with 2GB of RAM as standard. This is a reasonable base configuration, though with RAM prices so low at the moment you may be tempted to get the maximum 4GB. Unlike Windows Vista, the Mac operating system has no problem making full use of this much memory.

Graphics performance is a perennial sticking point for PC users contemplating an iMac, and although the graphics cards have been improved, they're still not stellar. The standard unit is a very modest ATI 256MB Radeon HD2600 Pro, which is fine for most tasks, but not demanding games or serious 3D editing. The good news is that for £90 you can upgrade to a 512MB nVidia GeForce 8800GS - still a mid-range rather than top-end card, but enough to cope with most games as well as boosting 3D and video effects rendering. Note that all upgrades have to be specified at the time of ordering, whether from the online Apple Store (www.apple.com.ukstore) or an authorised dealer; you can't swap components later. Units built to order take a couple of weeks to arrive from China.

The 2.8GHz 24 inch iMac comes with a 320GB 7200rpm SATA hard drive, which you can upgrade to 500GB, 750GB or 1TB. At £180, the 1TB option is too expensive, but £30 extra for 500GB is reasonable, and 750GB for £90 is worth considering. Given the very useful Time Machine backup feature in Mac OS X 10.5, it makes sense to invest in an external hard disk too - Western Digital's My Book Studio Edition, £150 for 1TB from www.amazon.co.uk, has FireWire 800 for the fastest connection to the iMac, and matches rather nicely.

The low-profile keyboard has been retained. With its Scrabble tile keys, it takes a heck of a lot of getting used to, especially if you like big, clacketty keyboards with lots of tactile feedback, but becomes very usable over time. The Mighty Mouse, with its invisible buttons, silly side triggers and handy but unpredictable scroll knob, is harder to love. Wireless versions of both are optional.

Missed connections

For further accessories and peripherals there are just three powered USB 2 ports (plus two on the keyboard, one occupied by the mouse), as well as one each of FireWire 400 and 800. So you're very likely to need a powered USB hub to connect all the devices you want, especially with no memory card reader or TV tuner built in; not a big expense, but it detracts from the system's neatness. The latest, fastest versions of Ethernet, WiFi and Bluetooth are also included, and there's a mini-DVI output to which you can connect a second display, either mirroring the iMac's screen or spanning your desktop across both. Annoyingly, there's still no way to use the built-in screen to display output from another computer.

Like other current Macs, the iMac ships with Mac OS X Leopard, the latest version of Apple's operating system. It's perfectly happy to run Windows Vista instead (switching between them on startup), but you'll need to buy your own copy. You also get Apple's well regarded iLife suite of applications for organising photos, editing movies, making music and (less convincingly) creating basic websites.