Conclusion: FireWire Gives The Best Results
The performance of the Western Digital external combo drive in our tests displayed a trend that we have repeatedly observed with other hardware components: you can achieve a substantially better performance with FireWire than with USB 2.0, even though USB offers a theoretical throughput of 480 Mbps compared with "only" 400 Mbps with FireWire.
With FireWire, we achieved an excellent maximum data transfer rate of 38 MB/s. USB 2.0, on the other hand, maxed out at just 32 MB/s. So, the combo drive with FireWire is able to score 74 percent of the theoretically available maximum of 400 Mbps - a fine achievement. USB 2.0 stops at 53 percent of its theoretical maximum.
At the actual "heart" of the combo drive is the Western Digital WD2000 or the brand-new WD2500 from Western Digital, two outstanding drives with high capacities of 200 and 250 GB, respectively, as well as respectable performance - despite the fact that a substantial part of this is negated by the use of USB or FireWire.
With a little dexterity, the case can be opened to remove the hard disk, either to achieve higher transfer speeds by connecting the drive directly to an IDE controller, or to install an even bigger drive when these become available.
We would recommend caution when positioning the combo drive. Although the case only became lukewarm during our tests, it does contain a hard disk in the fast 7,200-rpm category. Therefore, you should always be sure to position the drive away from any obstruction, and where air circulates freely.
The drive is currently available on Western Digital's US website for $399 - a fair price for a lot of storage capacity and great flexibility. The 250 GB version will initially be a "Special Edition" with 8 MB cache, but its price should be far more. A network connection would be the icing on the cake, but at this price it is hardly possible. Until then, Western Digital would be well off to work on an interface that would allow simultaneous operation of the drive when hooked up to two PCs.
In our view, the only fly in the ointment is the less than generous warranty period of just one year. The strange thing is that the warranty period is the same for the Special Edition, for which Western Digital has always offered a three-year warranty, up till now.