A Best-Case Scenario
SuperSpeed USB (also known as USB 3.0) brings 5 Gb/s transfer rates to the world of portable devices. That level of performance even appears to compete with established storage standards like SATA, but it’s going to take a while for developers of USB hardware to catch up.
With proven performance and storage-specific features, such as native command queuing (NCQ), controller-based RAID support, and TRIM for SSD drives, eSATA is set to remain the standard for fixed external devices over the next few years. However, portable storage solutions usually don’t need those features, as hot plug and removal are often easier to manage without them, and the USB connector even provides enough amperage to power most pocket-sized devices, while larger storage alternatives and eSATA both require a separate power supply.
Today, most USB devices can’t even maximize the 60 MB/s limit of USB 2.0. But some of those devices don't need to go any faster than that. Portable mass storage is where we can reap the benefits of a faster interface, as it can take several minutes to transfer something as small as a movie file using USB 2.0. Notebook hard drives have already broken through the 100 MB/s barrier, and USB-2.0-to-SATA bridges have remained stuck at less than 40 MB/s. SSD drives are up to three times faster still, and even the left-over unit from your recent notebook upgrade is probably 50% to 100% faster than any USB 2.0 enclosure you can find for it.
Given that USB 2.0 is unsuitable for our high-capacity portable storage needs, we tracked down several pocket-sized USB 3.0 enclosures to put a few of our own 2.5” drives to better use, unfettered by the bottleneck imposed by last-generation's peripheral bus.