Western Digital's My Passport Studio is a portable hard drive that's bus powered - it doesn't include a power adaptor.
The My Passport Studio uses either a USB or FireWire 400 port. It has a mini FireWire 400 port (a design element we're not fond of), which requires a proprietary cable with a standard FireWire 400 connector on one end for connecting to your PC and a two-headed cable on the other end that connects to both the mini FireWire port and the mini USB port on the hard drive. The cable works fine, but since the My Passport Studio is a portable drive, it means you're mobile; being mobile increases the chances of leaving the cable behind or losing it. And the two-headed cable isn't a common cable you'll find at your local electronics shop.
If you don't have the special cable you can resort to USB. If your USB port provides enough power, the drive can run off USB power. If your USB port doesn't provide enough power and you have a pair of USB ports available on your PC or USB hub, you can use Western Digital's optional USB 2.0 Power Booster Cable, which has a single mini USB jack on one end that connects to the hard drive, and a pair of USB jacks on the other end for connecting to a pair of USB ports. However, USB 2.0 performance is slower that FireWire 400, up to 15 percent slower in some of our tests.
As is the case with most portable hard drives, the My Passport Studio's drive mechanism spins at 5,400rpm, slower than the 7,200rpm that most desktop drives run at. Other portable drives include FireWire 800 or eSATA connections to speed up performance, but the My Passport Studio includes only FireWire 400 and USB 2.0. That said, the drive's performance results were respectable, taking 46 seconds to copy a 1GB folder from the internal hard drive to the My Passport Studio via FireWire 400.
The hard drive's design is compact and attractive. The drive features a sliding port cover that doubles as a four-light capacity gauge and activity light. To use the capacity gauge feature, you'll need to install Western Digital's Drive Tools utility, the only software that ships with the drive. Western Digital doesn't include any disk utility software or a backup program.