LEGEND of GRAPHS
6GSSD miniS RR = Single 6Gb/s SSD* in FirmTek miniSwap attached to the HighPoint RocketRAID 2744 installed in PCIe x16 slot of the 2010 Mac Pro 6-core Westmere
Pegasus Tbolt = Single 6Gb/s SSD* in Promise Pegasus X4 Thunderbolt attached to the 'late 2011' MacBook Pro 2.5GHz Core i7's Thunderbolt port
6GSSD A330 RU = Single 6Gb/s SSD* attached to the Koutech ASU330 6Gb/s SATA to USB 3.0 bridge which was connected to the HighPoint RocketU USB 3.0 host adapter in PCIe x4 slot of 2010 Mac Pro 6-core Westmere
6GSSD LBDt TB = Single 6Gb/s SSD* in LaCie Little Big Disk Thunderbolt attached to the 'late 2011' MacBook Pro 2.5GHz Core i7's Thunderbolt port
MBAflash M2Go RU = Samsung 256G Flash Storage removed from 2011 MacBook Air mounted in OWC Mercury-On-The-Go USB 3.0 enclosure connected to the HighPoint RocketU USB 3.0 host adapter in PCIe x4 slot of 2010 Mac Pro 6-core Westmere
6GSSD Voyager RU = Single 6Gb/s SSD* installed in the NewerTech Voyager S3 USB 3.0 Dock which was connected to the HighPoint RocketU USB 3.0 host adapter in PCIe x4 slot of 2010 Mac Pro 6-core Westmere
MBAflash M2Go CU = Samsung 256G Flash Storage removed from 2011 MacBook Air mounted in OWC Mercury-On-The-Go USB 3.0 enclosure connected to the CalDigit SuperSpeed USB 3.0 ExpressCard/34 installed in the 'late 2011' MacBook Pro's ExpressCard/34 slot
6GSSD A330 CU = Single 6Gb/s SSD* attached to the Koutech ASU330 6Gb/s SATA to USB 3.0 bridge connected to the CalDigit SuperSpeed USB 3.0 ExpressCard/34 installed in the 'late 2011' MacBook Pro's ExpressCard/34 slot
Kingston HyperX CU = Kingston DataTraveler HyperX USB 3.0 64GB Flash Drive connected to the CalDigit SuperSpeed USB 3.0 ExpressCard/34 installed in the 'late 2011' MacBook Pro's ExpressCard/34 slot
Enyo Flash CU = OCZ 128G USB 3.0 Flash Drive connected to the CalDigit SuperSpeed USB 3.0 ExpressCard/34 installed in the 'late 2011' MacBook Pro's ExpressCard/34 slot
(* The single 6G/s SSD used in this test session was the TransIntl SwiftDATA 6GB/s 240G synchronous SSD. We got essentially the same results when testing with the OWC Mercury Extreme Pro 6Gb/s 240G SSD and OCZ Vertex 3 MAX iops 6Gb/s 240G SSD. )
INSIGHTS & ANALYSIS
None of the USB 3.0 enclosure/host adapter combos came close to the 5Gb/s (500MB/s) theoretical transfer speed of a single USB 3.0 data channel. And, as you can see from the graphs, the Pegasus Thunderbolt and miniSwap eSATA enclosures were twice as fast as the fastest USB 3.0 enclosure.
However, the LaCie Thunderbolt 2.5" 'notebook' enclosure was only slightly faster than the USB 3.0 enclosures and slightly slower than the ASU330 USB 3.0 bridge.
The Koutech ASU330 6G Device to SuperSpeed USB 3.0 Host Bridge Adapter is a "non-enclosure." We included it to show it was faster than other USB 3.0 devices when connected to the fastest USB 3.0 host adapter. We're hoping some USB 3.0 drive maker will adopt this true 6Gb/s SATA to USB 3.0 bridge for their USB 3.0 enclosure.
Not surprisingly, the HighPoint RocketU Quad USB 3.0 4-lane 4-port RAID host adapter produced faster write speeds than the CalDigit SuperSpeed USB 3.0 1-lane ExpressCard. Though we haven't tested the Sonnet Echo Thunderbolt/ExpressCard adapter, one trusted test lab reports read/write speeds half of what we saw when using the 17" MacBook Pro's native ExpressCard/34 slot. We will report our own findings when we have a sample of the Echo.
The Mercury-On-The-Go USB 3.0 enclosure is offered by OWC to consumers who upgrade the flash storage module in their MacBook Air. We installed the OWC 6Gb/s Aura flash module in our 'late 2011' MacBook Air. Then we took the Apple factory (Samsung) 256G flash storage module and installed it in the Mercury-On-The-Go. As you can see from the graphs, other than the ASU330, it's the fast single drive USB 3.0 solution available.
If you have either Thunderbolt or SATA support in your Mac, then USB 3.0 will offer no performance advantage for you. But if you want external storage transfer speeds faster than FireWire 400/800 or USB 2.0 built-in ports offer, it's an alternative worth considering.