Apple USB 3.1 Rev 1 Retina MacBooks : Not So Fast
Filed in: Peripherals

It's important to note though that Apple's implementation is just the 1st revision of the USB 3.1 standard. Rev 1 means any new devices connected to it will still operate at USB 3.0's 5Gbps speed. It won't be until full USB 3.1 SuperSpeed+ (Plus) chipsets are used in future Macs that the data transfer rates will bump up to SS+ 10Gbps speeds - and on a par with 1st generation Apple ThunderBolt devices.
In a way, that's okay. Very few Apple computer peripherals need or can even come close to maxing out a 5Gbps USB connection anyway. Really, only multi-drive RAID storage arrays and 4K video displays need that kind of bandwidth. (And in particular - PCIe based solid-state drive arrays.) As such, expect the industry-wide rollout of SuperSpeed+ to 10Gbps to be a slow one. It remains to be seen if, how and when Apple implements it across their MacBook and desktop line in the year ahead.