Review: Western Digital My Book Thunderbolt Duo

The My Book Thunderbolt Duo is a ‘dual-drive storage system’ from Western Digital aimed squarely at Mac users with Thunderbolt-equipped devices. The drive comes pre-formatted with Mac’s HFS+ file system, and it includes Mac OS X Raid configuration software.

The unit comes preconfigured for RAID 0 (stripe), which gives you the fastest performance and the full 4TB or 6TB capacity of the combined drives. You can switch that to RAID 1 (mirror) for data redundancy, but at half the capacity (2TB or 3TB). The unit can also be configured JBOD (‘Just a Bunch Of Disks’), which allows you to access the two drives individually. Changing modes only takes a couple of clicks, and 20-30 seconds rebuild time. When doing so, all data on the drives is lost.

We tested performance in RAID 0, connected to a Thunderbolt-equipped Sandy Bridge MacBook Pro. Working with 5GB files in Blackmagic Disk Speed Test, the unit averaged 227MBytes/sec write and 236MBytes/sec read.

Working with small files (64MB of 1KB files), write speeds averaged 1.83MBytes/sec, with reads stable at 2.11MBytes/sec. This test is really a worst-case scenario for file transfer, and the results aren’t too discouraging: this performance is better than Seagate’s FAT32-formatted Backup Plus drive, for example, as tested over USB 3.0 on Windows 7. Noise was minimal, even during our most disk-intensive tests and with the drive sitting right next to our MacBook Pro.

The hardware is simple as it gets: a power cable, and two Thunderbolt ports to allow daisy-chaining of additional devices.

Altogether, a good high-capacity external drive for Mac users, with the advantages of simplicity and user-replaceable drives. We hope to see a Windows version for those very few Thunderbolt-equipped PCs in the near future.