Thunderbolt: Faster Than USB 3.0; Three Winners Emerge
We know that Thunderbolt's maximum sequential throughput is close to the 1 GB/s mark, and Promise's Pegasus R6 has the unique distinction of saturating this new interface using six 3.5" hard drives. But it'd be wrong to assume that it takes $2000 to get the most out of Thunderbolt. Unlike USB, Thunderbolt was designed so that multiple devices can operate in parallel and still achieve their peak performance. You can get that same 1 GB/s from three or four peripherals doing 250 to 300 MB/s each.
This critically important advantage doesn't get enough attention. With USB, the interface bottlenecks performance, not the devices themselves. As an example, if you burn a DVD on a USB 2.0-based writer and write to a thumb drive, those conflicting operations could yield a useless coaster. Although USB 3.0 facilitates a lot more headroom, the technology is similar, and bottlenecks remain probable.
Thunderbolt alleviates interface limitations. Yeah, one LaCie 2big can "only" hit 350 MB/s in sequential reads. But a second 2big in the same chain can hit 350 MB/s, too. You can use those two drives, plus something like BlackMagic’s Intensity Extreme (a Thunderbolt-based external capture device used by professionals to edit 1080p content) and not have any of those three devices stepping on each others' toes. If that matters to your application, then spending money on high-end hardware probably isn't your top concern.
For everyone else, though, Thunderbolt does still face a big pricing problem. Even one 4 TB 2big at almost $600 reflects heavy mark-up. If you have room for a quartet of 1 TB disks inside your case, they'd only run about $360.
Those fat premiums will hopefully slim down over time. But even at a more attractive price, several of the devices in our round-up are haunted by other issues that call into question their utility. Elgato’s Thunderbolt SSD, for example, suffers from poor throughput because it employs an SSD based on SandForce's first-gen controller technology. That's fine for moving personal data around. But it's far less adept at handling encoded media files. Surely, a $420 price tag for 120 GB of capacity doesn't help. Seagate’s GoFlex Ultra-Portable Thunderbolt Adapter is only able to operate as an endpoint device. You can use it in a daisy chain, but you have to give up the potential for outputting to a display with a mini DisplayPort adapter.
Western Digital’s My Book Thunderbolt Duo competes directly with LaCie's 2big, but is hurt by slower drives. The thing is, the My Book Thunderbolt Duo costs $50 less than the 2big, which is a reasonable trade-off, so long as you're also able to accept the plastic case. They both offer notable value, earning LaCie's 2big 6 TB and Western Digital’s My Book Thunderbolt Duo 6 TB our 2012 Recommended Buy Award.
If you'd rather manage just a single Thunderbolt-based device (count us in), you can't ignore the incredible performance enabled by Promise's Pegasus R4 and R6. The SSD version of the R4 isn't final yet, but we're certainly impressed with our early preview.
Performance and value are still vital criteria, though. The least-expensive Pegasus R4 costs 33% less than the R6, and sacrifices the same margin of sequential read performance. However, both units serve up identical sequential write speeds, making the R4 a better value. That also earns Promise's Pegasus R4 our 2012 Recommended Buy Award.
