LaCie Little Big Disk Thunderbolt Series 2TB hard drive

If you’re the owner of a new MacBook Pro, MacBook Air, Mac mini, or iMac, and you’re looking for something to plug into the fancy new Thunderbolt port, your options are pretty limited. There’s the Apple Thunderbolt Display ( ), the Promise Pegasus R4 and R6 RAID arrays, and now the Little Big Disk Thunderbolt Series from LaCie.

Like the other products in LaCie’s Little Big Disk line, the Thunderbolt Series drives are aluminum, portable external two-drive RAIDs. The drives can be configured as mirrored or striped arrays by using OS X’s Disk Utility.

Actually using the Little Big Disk Thunderbolt Series requires the purchase of an Apple Thunderbolt cable ($50), bringing the total cost of the 2TB version to $550. That’s nearly double what a 2TB, portable drive with a quad-interface might cost. LaCie doesn’t sell a 2TB version of its Little Big Disk Quadra, but its 1TB Quadra costs $100 less than the 1TB Thunderbolt version and the Quadra comes with all of the cables you’ll need.

As with the other Thunderbolt drive we’ve tested (the Pegasus R6), the Little Big Disk Thunderbolt Series of drives has only one connection type, a pair of Thunderbolt ports. Sure, Apple sells a lot of Macs with Thunderbolt ports onboard, but these drives would be much more useful with an assortment of connectors. With the two Thunderbolt ports, however, you can daisy chain more Thunderbolt devices, or an Apple Cinema Display with Mini DisplayPort.

And while the LaCie drive is that its meant to be portable, it requires external power. If the drive requires external power, why not use a design that uses 3.5-inch drives that are generally faster and less expensive than the 2.5-inch drives that are used?

That said, the LaCie drive is fast—at least twice as fast in most tests than a similar RAID array that we tested, the Avastor XMR Mobile RAID Drive ( ), which was tested using FireWire 800. Whereas the Avastor topped out at about 75.0MBps throughput, the Little Big Disk topped 207MBps in the AJA System read test and 190.0MBps in AJA System write test. When reading a 2GB file, the Little Big Disk sped along at 167.0MBps, compared to 74.5MBps for the Avastor.

When compared to the Pegasus R6 12TB RAID array, the LaCie definitely held its own on the file and folder transfer tests, especially the 2GB file read which the Pegasus was just 6 percent faster than the LaCie. That performance gap increased to 15 percent on the folder read test, 22 percent on the file read and 27 percent faster than the LaCie on the folder write test. The AJA System Test showed more of a difference between the two, with the Pegasus reaching 707.6MBps on the write test and 532.0MBps on the read test.

Macworld’s buying advice

If you don’t have a Mac with Thunderbolt, then this device is not for you as it doesn’t offer any backwards compatibility. If you do have a recent Mac with Thunderbolt, especially a MacBook Air, then the Little Big Disk is the least expensive, smallest Thunderbolt drive, and fastest portable hard drive currently available. An SSD version of the Little Big Disk Thunderbolt Series will be coming to market soon and I’m anxious to see the test results for that one.

[James Galbraith is Macworld’s lab director.]