Seagate’s GoFlex Thunderbolt adapter: High transfer speed, relatively cheap

If you bought a Mac (s aapl) last year, you probably have a Thunderbolt (s intc) port on your computer doing nothing right now. At CES 2012, we saw a lot of Thunderbolt solutions on display, but few are shipping yet. As of Wednesday, however, Seagate’s GoFlex Thunderbolt adapter (s stx) is available to order, which means you could soon be transferring data to external drives at lightning speeds.

The GoFlex Thunderbolt adapter isn’t exactly cheap at $99.99, but it’s still a far cry cheaper than most currently available dedicated Thunderbolt drives. At Apple’s online store, for instance, you’re looking at spending $499.95 just to get in on the ground floor with LaCie’s 1TB Little Big Disk Thunderbolt drive. By contrast, you can get a GoFlex 1TB drive starting at $159.99, plus the adapter for $99.99, bringing you to just under $250. Both solutions also require you to purchase a $49 Thunderbolt cable separately, of course, but at least pricing for Thunderbolt solutions is headed in the right direction for wider consumer adoption.

GoFlex’s option also works with their line of GoFlex-branded portable drives, so you actually only have to buy one adapter to use it with multiple drives. There are some caveats, however. The adapter doesn’t offer Thunderbolt daisy-chaining, but on the plus side, it also doesn’t need an external power source.

The other limit is that transfer speeds are capped by the drive’s capability. Macworld ran some real-world usage benchmark tests and found that while the 5,400 RPM drive found in Seagate’s Ultra-portable line transferred data faster on Thunderbolt than on FireWire 800, the gains weren’t huge. But with 7,200 RPM drives like those in Seagate’s higher-end GoFlex externals, you’ll see more benefits from the Thunderbolt adapter.

At $300 total before taxes for a 1TB drive, Thunderbolt adapter and Apple Thunderbolt cable, I still wouldn’t call this drive solution cheap, but it definitely lowers the barrier for entry. The upside is that you can add additional drives for much less after you have the adapter and cable, so long as Seagate keeps its GoFlex interface spec the same for future devices. That makes this probably the most consumer-friendly Thunderbolt storage solution we’ve seen to date.