There’s no such thing as a USB 3.1 data-only port that is compliant with all
However, some manufacturers use cheaper USB ports, by only implementing some of
One of the most common omissions is that of power charging, since data transfer
alone needs less power than does charging.
One can see this more clearly by examining USB Type-C cables, which
by definition should offer up to 10Gbps data rates and 100 watts of power.
However, many cheap USB cables designed for data transfer can only supply
about 10Wh of power, insufficient for many devices such as the Apple MacBook or
Google Chromebook Pixel 2 that charge at 29Wh.
USB 3.0 ports can only be used for data transfer. Users of USB 3.0 devices
devices can purchase adapters allowing them to use the newer USB 3.1 Gen 1,
but again, for data transfer only.
My opinion is that the specifications of the Asus ZenBook mean just that:
The USB 3.1 port is only a frontal adapter to older (and cheaper) USB 3.0
A full implementation of the USB 3.1 standard means the USB port can do a lot of things: Data transfer, video and charging. The Thunderbolt 3 specification piggybacks on USB 3.1 ports, meaning that manufacturers like Apple can make computers with USB 3.1 ports that are also Thunderbolt ports.
"USB 3.1 Gen 1 (data transfer only)" means therefore the USB 3.1 protocol,
but at half the speed and without video, charging, or Thunderbolt capabilities.
As most USB 3.X devices can negotiate capabilities with the port or the cable,
most USB 3.1 devices using data transfer will still function,
but at lower levels of performance.