You are looking at £350 more ex-VAT for the Rock Sigma Si than you would pay for the budget NEC Versa Premium, also reviewed in this group test, but you get a noticeably more pumped-up core specification for your money.

For a start, the Rock Sigma Si is based on a 1.2GHz Pentium III, although it is a general purpose Flip Chip rather than the notebook-specific Mobile processor, so it runs hotter and uses more battery power.

Deferring to the truth about Windows XP, Rock sensibly supplies 256MB of memory as standard, rather than last year's basic helping of 128MB. The big numbers also make it down into the hard disk department, where you will find a capacious 30GB of storage awaiting your data.

The largesse extends to the optical drive, which turned out to be a combo unit providing 8x DVD playback and 20x/4x/4x CD-RW from a single tray. Once again, the drives are fixed, not removable, but the dual functionality on offer means there's less potential need for modularity.

Things go off the boil slightly when you get to the graphics, which are powered by an SiS 630 accelerator integrated into the motherboard chipset just like the one used on the NEC Versa Premium. It too grabs a chunk of memory from the main system, but with 256MB to start with the loss is not going to cause any problems.

The expected 14.1-inch XGA TFT screen puts in an appearance, but once again it turned out to be reasonably bright and so drew no criticism. Extras in the Rock Sigma Si include a 10/100Base-TX networking adapter and a modem, both integrated, plus a FireWire port, a copy of Windows XP Professional and one year's collect and return warranty.

Omissions which might cause the odd headache are the lack of a serial port (you do get parallel and two USB though) and no expansion bus for a port replicator. We also felt that the 1 hour 30 minutes or so of battery life was somewhat on the low side.

The keyboard on the Rock Sigma Si wasn't one of the best, with rather undersized Enter and Backspace keys, and once again you get a plastic lid so you will need to be careful about screen damage if you travel with the machine regularly.

These are all niggles rather than catastrophic failures, but added up they do rob the Rock Sigma Si of the clear-cut edge it could have had.