I recently purchased a USB 3.0 portable hard drive. The transfer speed is about 100 MB/s when connected directly to the 3.0 USB port on my Surface Pro. When I connect it to a 2.0 USB hub, it transfers at about 40 MB/s. I was expecting a transfer rate more like along the lines of 500+ MB/s. Is the 100 MB/s speed a typical transfer rate for USB 3.0 connections? Am I expecting too much from a USB 3.0 connection? Is there a setting that is limiting my 3.0 port? Any help would be appreciated. Thanks.