Thunderbolt-equipped LaCie desktop drives hit the Apple Store

Slowly but surely, Thunderbolt (s intc) accessories for Apple’s Mac (s aapl) computers are making their way to retail. On Tuesday Apple began selling the LaCie Little Big Disk in both 1 TB and 2 TB capacities with Thunderbolt connectivity. The drives retail for $399.95 and $499.95 respectively and ship in one to two weeks.

LaCie’s desktop RAID drives feature either two 500 GB 7200 RPM or two 1 TB 5400 RPM hard disk drives mounted in a single case, and each features two Thunderbolt connectors for attaching to your computer and for daisy-chaining with other Thunderbolt-equipped accessories. Mini DisplayPort monitors can also connect to the LaCie Big Disk Thunderbolt series, but one of those must cap the daisy chain if you plan to use it with other Thunderbolt devices.

The drives are light, at 1.4 lbs each, and can achieve transfer rates of 251 MB/s. If you daisy chain four together, LaCie says you can hit even higher speeds, up to a maximum of 782 MB/s. Note that this would also require four Thunderbolt cables, which Apple sells for $49 each. And the LaCie drives don’t ship with a Thunderbolt cable .

LaCie’s target market with these drives is creative professionals who needs need the speed of Thunderbolt and also a conveniently portable form factor. The Little Big Disk is a much cheaper option than the Promise Pegasus RAID System, which debuted in June and starts at $999 for a 4 TB version. Still, it probably won’t appeal to the average consumer for whom an equivalent 1 TB drive at around $70 or a little more with USB or FireWire connectivity is more than adequate.

If I did just a bit more video and photo editing than I do now, I can see the LaCie being a good option for an external project scratch disk. LaCie also supposedly has an SSD option on the way, but that will likely be even more expensive. Anyone else thinking about grabbing one of these?