Labs

Western Digital's My Book Mirror Edition is chunkier than the other desktop disks here, as its glossy black case contains two 1TB disks. A simple software utility lets you combine the two disks in a RAID 0 array to provide 2TB of storage space, but you'll lose all your data if one disk fails.

You can also configure the disks as a RAID 1 array, halving the available storage space but ensuring

ADVERTISEMENT

your data is safe if a disk fails. It's a shame that no backup software is included, but RAID 1 partially makes up for this.

A push-button lid provides easy access to both disks, so you can replace them quickly if necessary, although you'll still need to attach the included plastic handles to each disk. This is an advantage over Freecom's RAID-capable - but sealed - Data Tank, which needs to be sent back to the manufacturer for servicing in the event of a disk failure.

The Mirror Edition has only a USB port, unlike the FireWire-equipped Data Tank. It didn't dominate our benchmarks, whether it was configured as RAID 0 or RAID 1, but it wasn't far behind the front-runners.

If you simply want lots of storage space, you could buy two 1TB Freecom Hard Drives and save £50. However, if you're more concerned about keeping your data safe, the Mirror Edition is a good buy: it's the cheapest RAID 1-capable external disk we've seen that has easily replaceable disks.