I bought a Gigabyte AiVia Osmium keyboard today. But I have been wondering of you need to plug in the USB 2.0 cable to get it to work. I can't get it to work if I only plug in the USB 3.0 cable. Do I need to plug in both the USB 2.0 and USB 3.0 cable to get the maximum speed? And is it normal not being able to get it to work if only using the USB 3.0 cable?