Thunderbolt drives like the LaCie Little Big Disk Thunderbolt (240GB SSD) are a rare breed at the moment. And, because of their high prices (the LaCie costs costs $899.99 list), you have to have a profitable, billable project like a six-month graphics production contract to make it worth the extra money over a FireWire 800 drive. The Little Big Disk is the "saner" alternative to the Promise Pegasus R6 ($1,999 list, 3.5 stars) line of hard drives, though in the end you're still going to pay a lot of money for a little storage. There are good reasons to get the LaCie Thunderbolt drive instead of more commonplace spinning hard drives, but even so it's strictly for professionals.

Design and Features
The Little Big Disk (LBD) Thunderbolt looks identical to its predecessor, the LaCie Little Big Disk Quadra ($450 list, 3.5 stars), from its all-aluminum construction to its compact 1.6-by-3.3-by-5.5-inch (HWD) chassis to the LaCie-brand-ID blue-LED-lit hemisphere embedded in the drive's front face. The LBD has the same ribs extending down the sides of the case to aid cooling. It's a nice bit of industrial design, but the single fan will still make its presence known with a constant droning whine. On the back is a pair of Thunderbolt ports, which can be connected directly to your Mac, an Apple Thunderbolt Display, or daisy-chained to another drive like a second or third LBD or Promise Pegasus R6 (the only other Thunderbolt drive model on the market so far). Like the Pegasus R6, the LBD comes in a few capacities: 2TB (5,400rpm), 1TB (7,200rpm), and 240GB (SSD) (our review unit, the fastest and most expensive). The chassis houses two 120GB 2.5-inch solid-state drives (SSDs) in a SATA RAID array, allowing more potential bandwidth than you'd get from a single SSD or spinning hard drive. LaCie claims that chaining together four or more LBD drives will get you up to 800MBps throughput.

The drive also comes with an AC power adapter, a screw-on desk stand, and a utility CD that contains the drive's manuals and a full copy of Intego Backup Manager Pro, which gives Mac owners more control over data backup and restoration than Time Machine does. The drive works perfectly well with Time Machine, and is formatted for the Mac-native HFS+ file system out of the box. The drive comes with a three-year limited warranty, which is better than the one-year standard warranty that comes with more pedestrian drives. One thing missing is a Thunderbolt cable: Thus far the $49 Apple Thunderbolt cable is the only one on the market, and you'll need at least two if you want to daisy chain your LBD Thunderbolt drives together.

Performance
Performance is the reason why you'd buy the Little Big Disk over, say a $50 Western Digital My Passport Essential 250GB USB 2.0 drive. The LBD took only 11 seconds to transfer our standard 1.22GB test folder to the drive via Thunderbolt; the same task took 22 seconds via FireWire 800 and 35 seconds via USB 2.0 with our latest Mac Storage Editors' Choice, the Iomega eGo BlackBelt Mac Edition ($199.99 list, 4 stars). The speed demon Promise Pegasus R6 needed only 6 seconds, but that's with a six-bay hard drive array, and of course it costs more than twice what the LaCie drive does. Because we can't run Futuremark PCMark 7 on a Mac without emulation, we used AJA's System Test to check out each drive's performance, and the LBD was fast: 476MBps read and 252MBps write. The Promise was significantly faster on write operations (480MBps read, 620MBps write on Thunderbolt) and the eGo BlackBelt was a lot slower (46MBps read, 48MBps write on FireWire 800). Essentially, the LaCie slots in nicely as the "entry-level" drive for Thunderbolt, for those who need more speed than the older FireWire 800 standard can provide.

The LaCie Little Big Disk Thunderbolt (240GB SSD) is kind of in its own category these days. It's a fast two-drive non-upgradeable external, which is a lot more pedestrian than the über-drive Promise R6 RAID array. The Promise is the scratch disk you want if you're into HD video production on the Mac in a studio. The Little Big Disk is better suited for people who spend all their time in Photoshop or doing portable HD Video production, or people who absolutely need to transfer files from one Thunderbolt-equipped Mac to another (when the Macs are too far away to use a Thunderbolt cable). The LBD is a good solution for MacBook Air users, but I'd probably recommend the 1TB or 2TB version as a data drive to supplement that system's relatively small 64-256GB flash drive. As it is, the Little Big Disk is the Thunderbolt drive to buy if you're thinking of spending only a slightly insane amount of money.

COMPARISON TABLE
Compare the Buffalo MiniStation Cobalt USB 3.0 with several other hard drive side by side.