Western Digital My Book Thunderbolt Duo

The Western Digital My Book Thunderbolt Duo ($849.99 list) is one of the largest capacity drives you can buy. Dual 4TB drives together in a RAID 0 array means that you can hold up to 8TB on one logical volume. While this technically means you can store files larger than 4TB (like raw video or a massive database), it also means you can store a mind-boggling large number of smaller files (say every photo a professional photographer has taken since 1997, in native RAW format). It's a prime choice if you need all that space, but there are faster drives out there that take better advantage of the next generation Thunderbolt port. Think of it as a future-proofed bucket for all your files.

Design and Features
The My Book Thunderbolt Duo comes in a silver colored 6.5 by 4 by 6.25 inch (HWD) desktop drive enclosure. It looks very much like the still available ($499.99 list, 4 stars), aside from the fact that the WD Studio Edition II has a capacity gauge its front panel. Instead, the Thunderbolt Duo has a simpler power/drive use LED. In the back are two 10Gbps dual-channel Thunderbolt ports, the jack for the AC adapter, and a Kensington lock port. Unfortunately, the Thunderbolt Duo lacks a USB 3.0 port or FireWire 800 port, both of which would be helpful if you ever needed to transfer files with a PC or Mac that lacks a Thunderbolt port. Make sure to transfer files from your old drive over the network or using a Mac with both types of ports.

The My Book Thunderbolt Duo comes with two capacious 4TB Hitachi hard drives pre-installed, and configured for RAID 0 (striping). This isn't as odd as it sounds, since Hitachi and Western Digital are now corporate cousins. This gives you 8TB of storage, which is one of the largest capacities available in a desktop drive enclosure. You can use the included WD Drive utilities to reconfigure the Thunderbolt Duo as a RAID 1 array (protected 4TB drive) or as a pair of individual 4TB drives (JBOD). You can pop the top panel open with a touch, exposing the drive cage. After undoing a thumbscrew and lifting out another panel, you can access the My Book Thunderbolt Duo's two drives. This is handy for the sorts of folks who burn out hard drive mechanisms often, like video editors. You can ask Western Digital for replacements during the drives' three-year warranty. The drives come pre-equipped with slide in pegs and easy to use handles, so you can replace them a few minutes without using a screwdriver.

The drive comes with an installer for WD Drive Utilities, which lets you register the drive, set drive security (256-bit encryption), run diagnostics, format the drive, set the RAID level, and set a sleep timer for the drive. The sleep timer is important, since you don't want the drive to run 24/7 and risk burn out unnecessarily. The drive comes formatted for HFS+ (native Mac format), which means you can use it with Time Machine out of the box. The two Thunderbolt ports on the back are interchangeable; you can connect your Mac to one port, then daisy chain other drives or a display to the other port. Thankfully, the 8GB version of the My Book Thunderbolt Duo comes with one Thunderbolt cable, so you don't have to shell out an extra $49 for Apple's cable. Lower capacity versions (4TB and 6TB) do not come with a cable, so you'll have to add one to the cart when you buy the Thunderbolt Duo.

Performance
The Thunderbolt Duo's speed rivals that of a solid-state drive on some operations. The drive took a short six seconds to transfer our 1.2GB test folder, a faster time than the 17 seconds of the SSD-powered ($299.99 list, 4.5 stars), equal to the Editors' Choice ($999 list, 4.5 stars), and about twice as fast as the ($749 list, 4 stars).

The My Book Thunderbolt Duo is also a smidge faster than its faster cousin, the ($899 list, 4 stars) on the drag and drop test (11 seconds). However, the VelociRaptor Duo is a lot faster at the AJA system test, which simulates the sort of drive transfers that are commonplace in the video editing world. The Thunderbolt Duo is capable of good scores: 257MBps read and 263MBps write scores at the AJA system test. The VelociRaptor Duo speeds along with a 374 MBps read speed and 343 MBps write speed, handily beating the 2big drive (320MBps Read, 304MBps Write), but coming in behind the Little Big Disk (620MBps read, 380MBps Write). This means that the Thunderbolt Duo is fast, the Velociraptor Duo is faster, but the Little Big Disk is the fastest. Granted, they all have different capacities and markets, matching their relative speeds.

The My Book Thunderbolt Duo concentrates on capacity. Weighing in at 8GB, It's one of the largest capacity drives we've tested short of a multi-disk NAS array. It's larger and faster than older FireWire 800 drives by a long shot. It's also much larger (but slower) than its speedy sibling the Western Digital My Book VelociRaptor Duo (2TB), and all are significantly slower than the Editor's Choice for external drives, the La Cie Little Big Disk Thunderbolt (1TB). If you absolutely, positively need 8TB for your large database, scientific, or graphics files in a single volume and are looking to keep your drive future-proofed, then the My Book Thunderbolt Duo is a very good choice, but there are faster drives (with much lower capacity) at this price point.

The Western Digital My Book Thunderbolt Duo comes in as a high-speed drive for graphics designer and scientific professionals. While not as capacious as the LaCie 2Big Thunderbolt, it is significantly faster. It's also faster on write operations and has much more capacity than SSD-powered solutions like the LaCie Little Big Disk and Rugged Thunderbolt solutions. The ($1,999 list, 3.5 stars) has a larger capacity and greater speed, but my goodness look at the price tag. The current external drive EC, the ($299 direct, 4.5 stars) holds on to its title thanks to its rugged, fire-proof construction and included data recovery service, but the Thunderbolt Duo is a great choice for Mac professionals and any specialized PC user that needs the speed of Thunderbolt enough to seek out and buy one of the few Thunderbolt-equipped PCs.

COMPARISON TABLE

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