Software RAID, simply because it's the only way they can fit everything into a USB thumb drive the size of a pack of Wrigley's chewing gum.

Real, actual, hardware RAID requires a fully dedicated controller designed for said purpose, along with its own RAM cache and heatsinks. Example 1 Example 2 I'd like to see these clowns attempt to shrink-ray one of these server cards into something small and power-efficient enough to run off USB 3.0.