If you want to use the Oculus Rift to its full potential, you're going to need four USB ports in total - three USB 3.0 ports, and a single USB 2.0 port.
The original recommended requirements for the Oculus Rift were two USB 3.0 ports, but now three USB 3.0 ports and a USB 2.0 port are required - something Reddit user 'Kontis' found on the new requirements for the Rift. Oculus founder Palmer Luckey replied to the thread, saying that the new requirements assuming that the Rift owner will be "using Touch and an Xbox One gamepad at the same time".
Luckey added: "Many people will be able to reduce port utilization with hubs, but your experience will vary by computer and hub. We want to be totally honest with the maximum-use scenario so people can prepare and not have to swap ports around depending on the game they play".
The release of the Oculus Rift CV1 headset is due in Q1 2016.