Western Digital My Passport Studio 640GB external hard drive

Passport is the apt name chosen by Western Digital for its range of portable storage devices, not much bigger than the 2.5in notebook drives they contain.

Western Digital My Passport Studio 640GB is the top model from the range, now more pocketable than ever thanks to extra-rounded corners - and attractive capacities. FireWire connectivity promises great performance too.

We tested the Western Digital My Passport Studio 640GB with a WDC Scorpio Blue drive inside. This relatively cool and quiet hard disk barely makes its presence known, even when busy.

More conspicuous are changes wrought to the outside of the Western Digital My Passport Studio 640GB. An e-label display allows personalisation with a single line of your choosing - name, company or contents - up to 12 upper-case characters.

Also shown is remaining capacity, and a padlock to denote whether the drive is locked - an option from the included WD SmartWare suite. When activated, you're required to enter a password to access drive contents. This is true 256-bit full-disk hardware encryption too, always on whether you set a password or not.

The Western Digital My Passport Studio 640GB unit is immaculately finished in silver and white plastics. On the bottom are micro-USB 2.0 and one FireWire 800 port. Unlike previous generations, the single FireWire means you can't daisy-chain to additional devices. Nor is there a sliding hatch now to help keep out dust, or a soft carry pouch in the box.

But at least Western Digital has ironed out the bug that prevented the My Passport Studio from being used for FireWire booting in OS X.

The SmartWare app walks you through setup - label, then locking, and finally the backup software. This automates backup of all or part of your user files to the Western Digital My Passport Studio 640GB. The virtual CD that appears every time you plug in the drive can be switched off here.

WD's Flash-based app can be heavy on system resources though - we saw up to 90 percent CPU usage just cataloguing files before backup.

In lab tests, the Western Digital My Passport Studio 640GB performed well. Tested with HD Tach and HD Tune Pro tools, USB showed read speeds up to 31MB/s and writing at just 15MB/s - not untypical results for USB 2.0.

We used the included adaptor cable to measure 34MB/s and 32MB/s respectively, for read and write speeds over FW 400. And over FW 800, the Passport excelled with average read/write speeds of 56MB/s and 44MB/s.