The final issue is that, although USB 3.0 is capable of 400 MB/s, its performance potential is impeded by an inefficient protocol. Overall, though, the most consistent experience comes from USB native to a Platform Controller Hub or Fusion Controller Hub. Etron's controller on one board tops out at 250 MB/s, and then the same controller on another platform can't get past 200 MB/s. With that said, we've seen conflicting performance numbers, and the results almost seem to be implementation-specific.
The aforementioned benchmarks were run on an ASRock Z77 Extreme6 motherboard’s native USB 3.0 ports. Second, the host's controller significantly influences performance. But that advantage alone isn't enough to push past 300 MB/s to the interface's peak potential. Thus far, in our experience, USB 3.0 devices employing ASMedia controllers deliver the best performance. Now, the BlacX 5G is the only device of the three mentioned that uses an ASM1051 controller.
More impressively, the BlacX 5G is capable of outperforming Buffalo's external RAID solution, which shows up in the chart above that. In the chart above, Thermaltake's BlacX 5G is clearly capable of overtaking Apricorn's SATA-to-USB 3.0 Adapter, though you're only going to see those numbers if you use a high-performance SSD. The first answer to our question is that the device-side controller significantly influences performance.