Current output of usb 3.0

[Magnum]

I am trying to determine what the current output is for a usb 3.0 port.

I use it sometimes for charging my phone but noticed it charges slower than a wall charger.

I read some info here, but the consensus is mixed.

https://superuser.com/questions/690074/what-is-the-power-output-of-a-usb-port