Incidentally, I have two more USB ports at hand none of my three plates. Always only one, even on the Hub works. Both of my Toshiba laptop, my Sony desktop and now the Mac Mini. In the latter case, I use the 160's as full partition, all other plates were too loud. The Mini is just as quiet, even with a 5400 disk and what is offered specifically for on plates, is very nice to look at, but at least three times as loud as the Mini itself or the Trekstors.
The only drawback for me - you have to pull out the USB connector when you disconnect the drive or does not want to run with. There is no off switch, but that does not work well due to the system. On a Windows computer, the drive stays on even after turning off the computer, because it still draws power via USB. For Mac users, it then goes out after all - but not at rest, I use mostly, I have to pull the connector there.
If you really looking for a quiet and portable drive to get to the gates Trek in my experience is not over.