Problem with USB2 port with FTDI while using Sparkfun ESP8266 Thing Dev

Projects Networking, Protocols, and Devices
1

When I connect Sparkfun ESP8266 Thing Dev with my notebook USB2.0 port, I only see Com5 in my port (in Arduino IDE). It is not able to compile successfully, with error

error: Failed to open COM5
error: espcomm_open failed

But when I change to USB3.0 port, it is able to compile successfully. I want to understand is the FTDI is not supporting with USB2.0 ? I wish to understand the logic behind this.

2

The error occurs during upload. There is no problem with compilation.

FTDI chips definitely work with USB 2.0. In fact I don't think USB 3.0 even existed when that chip was designed.