I bought this thinking it would be able to drive more than one USB3 hard drive, with its extra 5V 4A supply. Plugged in one Hitachi USB3 hard drive, it worked like it did on the port by itself (yet much slower than an intel usb3 port). BUT plug in another hard drive from Seagate or Western Digital, it slows down to a crawl and the disks make clacking sounds. Clearly this does not actually work as a hub for multiple USB3 hard drives, returning it as probably broken? Anyone else have 4x USB3 hard drives plugged into theirs? Does it work?