Storage gets smaller and cheaper all the time. Sonnet's Fusion F2 RAID array is tiny – slightly wider than a CD case, around 20 percent deeper, and as thick as the bottom half of a MacBook Pro with the lid open.

The Sonnet Fusion F2 also weighs very little. Visually it's not quite as slick as, say, an Apple product, but doesn't exactly look shabby either.

Inside the tiny Sonnet Fusion F2 are two 320GB 2.5in drives, linked to the world via eSATA ports.

Installation went smoothly, and the only quirk is the fact that the Sonnet Fusion F2 uses three cables altogether – two eSATA leads for the drives, and a separate FireWire 400 power hookup.

The Sonnet Fusion F2 is bus powered, but because eSATA isn't, the power has to be borrowed from the F400 port. This ties up an F400 port when you may want it for other things, and it also eats into battery life – between 20-35 per cent in our tests.

It's not a neat arrangement – the two eSATA leads are required because in effect the Sonnet Fusion F2 is just two disks in a box.

On the plus side, the drives run quiet and are very cool. There's no fan, and only the barest hint of heat from the Sonnet Fusion F2's case. The drives are also supposedly shock isolated, making them more robust than usual.

OUR VERDICT

It's impossible to fault the performance or the size, but the three-cable hook-up system is a drawback. And the Sonnet Fusion F2 isn't cheap. Overall though, this is a powerful and portable product for on-location sound and video work.