Like the rest of the SpeedStep machines reviewed here (apart from the Rock), the Omnibook 900B is powered by the 650MHz SpeedStep PIII processor from Intel. What makes it unusual is that unlike the others - and most power notebooks - the emphasis is on portability. Both the reduced footprint and slimmed down 35mm thick case conspire to reduce the weight to just 2.1kg, which is well below the average for this class of machine.

In order to do this the designers have gone for a one-spindle design with an external floppy drive module. Irritatingly, HP charges £192 extra for the CD-ROM drive, but you might prefer to opt for a DVD-ROM player instead, as well as one or more of the other drive options which include a ZIP 100, an LS-120 and a second hard disk.

We noticed some flex in the body of the case, some give in the lid surface and a loose battery retaining panel, all of which placed a question mark over how robust this machine will actually prove to be on the road.

The other niggle was the spec that you get for the price: for such a large fist full of cash there's not only the lack of a CDROM to contend with, but there's also no modem and only 64MB RAM as standard, which makes this an expensive system, the 12GB IBM Travelstar hard disk notwithstanding.

Despite the reduced overall size the Omnibook retains reasonable ergonomics thanks to a 13.3-inch screen which delivers adequately readable XGA, and a keyboard that is properly laid out and big enough to be easily usable. You even get a combo pointing device giving you the choice between mouse pad or finger-joystick.

With SpeedStep enabled and running at 500MHz the battery should last around 2.5 hours, but we noticed that even with SpeedStep off and running at full speed the running time only fell by about 20 minutes, which might be good news if you really need the extra power, but as we've said, it doesn't do much for Intel's claims over the efficacy of SpeedStep as a power-saving technology.

Performance fell some way short of most full-sized 650MHz systems but the Omnibook is still very fast for a sub-notebook and ought to eat up the typically undemanding tasks for which most people use machines like this.

Hewlett Packard - Omnibook 900B price

£2,540 + VAT

Hewlett Packard: 0990 474747