USB 2.0 hard drives
IntroductionSince USB 2.0 is now included on most new Macs, it's time to look at what's available to plug in.
FireWire and USB were originally designed to do two different things: FireWire was an easy-to-use, fast storage interface; USB was a successor to ADB (Apple Desktop Bus), which we used to plug in our keyboards and mice. At some point USB got confused with a worthy interface for storage. It isn't; it's too slow. But that didn't stop people making USB drives. The only USB drives worth a look are the tiny solid-state storage keyrings. Hard drives using USB 1.1 are mostly pointless, unless you have a lot of time on your hands.
In theory, USB 2.0 runs at 480Mbps – that's faster than FireWire's 400Mbps. Of course, these figures bear little relation to real-world results and are based on a perfect scenario. In real life, the results are quite different.
We looked at three hard drives, from Maxtor, SmartDisk, and Iomega. Each has FireWire and USB 2.0, with the exception of the Maxtor, which is FireWire-only.
We tested each drive by copying a 1GB folder of 10MB files to and from an internal hard drive. We know from previous hard-drive tests that the top speed of the drive is in most cases set by the speed of the bridge rather than the speed of the drive. Only extraordinarily slow hard-drives would fail to keep pace with the interface, so the connection is the important part of the equation.
The two USB 2.0 drives differed quite wildly in their results, with the SmartDisk model performing at almost double the speed of the Iomega model. However, this is immaterial because the results from the FireWire tests showed that even FireWire 400 is much faster than USB 2.0. The Iomega drive was four times faster than USB 2.0 using FireWire, though its USB 2.0 results were particularly slow.
All three drives performed within seconds of each other in the FireWire tests. While Iomega got the best result by a whisker, it did require reformatting with Apple's Disk Utility. Its original format was problematic and unreliable, hence the reformat.
The Maxtor drive has some extra features: a single button launches Retrospect Express. This can simplify the backup process, and the Dantz software is long-established and well designed. The other drives also have software, but neither are integrated in the same way.