Oh,linuxdev.With your help,I almost understand this.I cannot appreciate you much more for your detailed explanation.
Now,another question comes to me which is stated in the following:
Nowadays,are there such a PCIe card which converts PCIe interface into several USB3.0 interfaces and it has four USB3.0 controllers(i.e.,four root HUBs) at the markets? If does,what’s the key words I can search for purchasing?