HDtune Pro Benchmark
Using HD Tune Pro, the sequential read write is tested. We see some very good results with USB 3 getting pretty close to what we get on SATA2. The difference is just a couple of MB/s. The interesting figure would be that we achieve 165MB/s for write compared to 148.7MB/s on SATA2.
Compared to USB 2.0, USB 3.0 gives a boost of performance of 4.5X faster in read and 5.3X in write.
In HD Tune Pro Random read/write test, the difference is noticeable. SATA2 definitely outperforms USB 3.0. Comparing USB 2.0 to USB 3.0, we see a 5 fold increase in performance using USB 3.0 vs USB 2.0.