Hi, yes so what I did was yet a USB splitter, so that I could connect my external mouse to one USB port and the external hard drive to the 2nd. I have a rather old system, so 3 1080p cameras and 13 960h cameras. The bitrate for the mouse and the cameras should be fine to go through USB, at least according to some online calculators. I bought a seagate external hdd enclosure too, so it has a sata port inside for the HDD and a USB out.