Hardware Review: Western Digital My Book Thunderbolt Duo

Since I have a Mac mini with a Thunderbolt connector, I’d been wanting to try out a Thunderbolt hard disk for some time. About a year ago, Western Digital My Book Thunderbolt Duo (that’s a name that needs shortening; I’ll just call it My Book in the rest of this article). I wrote a “first impressions” post back then; it’s time to update that.

I have a lot of data to back up, notably my very large music collection, plus important work archives. I have a very strict backup routine, where I back up my backups, and the fewer devices I have, the better. The My Book is a single unit holding two hard disks, with capacities of either 4 or 6 TB (I chose the 4 TB model).

There are many advantages to this type of device. Fewer power bricks and data cables make it easier to set up, and the single Thunderbolt cable allows me to connect it either to my Mac, or to my Thunderbolt Cinema Display. In addition, this device has no fan, which I really appreciate. I have long been on a quest for silence in my office, and the external hard disks that I use all day long are single enclosures without fans.

Setting up the My Book is very simple. You plug in the power cord, then the Thunderbolt cable (not included with the device; this costs about $50, though Western Digital now sells the device in a package with a cable, for about $50 more). Then, you can use Western Digital’s WD Drive Utilities to format the disk. It comes set up in a RAID 0 format, where the two disks show as a single 4 TB disk; this is the fastest way to use it. You can also use RAID 1 (redundant RAID), or JBOD (Just a Bunch of Disks) to have the two disks mount separately. I chose this latter option because I want the full 4 TB, but I also want multiple partitions. (You’ll need to use Disk Utility to partition the disks after you’ve set them up for JBOD in the WD Drive Utilities software.)

In real-world use, I get 80-90 MB/sec, or about 3 times the speed of FireWire 800. One of the limitations of this drive compared to others is that it uses 5900 RPM hard disks to save energy, and to keep heat low enough so it doesn’t need a fan. (That’s not a typo: these drives are indeed 5900 RPM.) So it’s not the fastest Thunderbolt storage device; if you really need speed, you’ll want something with faster disks.

But for me, this is sufficient, and my backups are much faster than before. It’s an ideal solution for a standard office setup. Of course, I’m comparing the speed to the previous fastest technology I had, FireWire 800. When I first got a Mac with FireWire 800, and got some compatible hard drives, I was amazed by how much faster they were than FireWire 400. I’m sure that, in a few years, this Thunderbolt drive will seem slow.

Another plus to the My Book is that, if necessary, the hard disks are easy to replace. I’m not planning on them going bad, but if, in a few years, I need larger disks, I can switch them (as long as they are Western Digital Caviar Green drives; the devices only works with these, again, because of the heat they give off).

I’m very happy with this drive. It has replaced two individual drives that were connected to my Mac via FireWire 800, and it gives me the flexibility of connecting it either directly to the Mac, or to my Cinema Display. At around $500, this drive isn’t cheap – and don’t forget to factor in the $50 for the cable – but it’s good value for the money. It’s easy to set up, fast, and it’s quiet. Exactly what I wanted.