I did not buy this for these two USB3 external access but to add to my motherboard (Asus Z97-A) an additional connection usb3 - 20 pins. The purpose of this choice is rather to be able to connect a memory multi-card reader (in this case a Icybox IB-865-B) equipped with a PC usb3 taken facade. Another advantage, not least, this type of connection is simple, clean and unmistakable. Everything is being assembled, so no technical opinion on the matter.