There are usb 3.0 devices that reduce energy use, fewer of the remaining 4 v 4.4 v, but adds a lot more speed in the transmission power of 500 ma to 900 ma.
In addition, USB 3.0 can reduce energy usage less equipment from 4.4 V to 4 V the rest but increase the speed at which energy was sent to the 500 mA is 900 mA.
In addition, reduce USB 3.0 the use of the device. Less energy from 4.4 to 4 V V but increase the speed of the transmission power, a lot of up to 900 500 mA mA