The read throughput we’ve seen on the Crucial and iStarUSA devices is very close to the maximum performance we achieved with the test drives when they were operated on the internal reference storage controller. iStarUSA is able to capitalize on the full real-life maximum throughput of USB 2.0, which is approximately 32 MB/s, while Crucial’s SK01 kit stays below 27 MB/s. The Unitek SATA HDD Dock achieves nice USB 2.0 throughput even when using a high-speed 266x CompactFlash card—clearly, the card reader is a high-performance device.
The results are similar for the write performance tests. USB 2.0 limits the throughput of all devices to 25-27 MB/s write transfer rate, while eSATA allows all products to unleash the full performance of the drives they host.