Performance

USB 3.0

With most external enclosures, the performance is determined by what you choose to install within the case. While we have used traditional hard drives in the past, we are now able to push most external hard drives to the limit of their USB 3.0 connectivity through the increased performance of SSDs. As you can see above, the Rosewill RDEE-12002 manages around 220MB/s read and just under 160MB/s write performance. All well beyond what you would ever get from USB 2.0. But is there a benefit to the internal SATA 6Gbps interface when compared to a traditional SATA II one?

Quickcheck: SATA performance

We connected the SSD utilizing one of the latest generation SATA 6Gbps controllers, also found in Plextor SSDS, directly to SATA II and SATA 6Gbps. With the aging interface, the drive managed to push around 10% less read but slightly more write than with the Rosewill enclosure. However, moving things up to the newer SATA standard resulted in speeds well beyond what the RDEE-12002 was able to deliver. This means that the bottleneck is still the USB 3.0 interface chip or the USB 3.0 interface on your motherboard, and that an enclosure with an internal SATA 6Gbps interface will only give you a small benefit over the second generation one.

USB 2.0

USB 2.0 performance is completely maxed out with the RDEE-12002. It pushes almost exactly 35MB/s read performance all the way across, while write performance hovers at 30MB/s—we would expect nothing less.