usb 2.0 port problem

NANO has 3 usb 2.0 ports(0, 1, 2).

Is the transmission speed of each port 480Mb/s?

Or are three ports sharing 480Mb/s?

I am going to use 4 cameras.

The transmission speed of each camera is about 200Mb/s.

Can I connect 2 cameras to usb port0 and others to usb port1?

The Development carrier board has 4 USB 3.0 ports and one USB 2.0 port that can only be used in device mode. You should be fine. If you have the production module, it will depend on your carrier board. You will likely want a powered hub in any case. Also note that USB cameras will likely not perform as well as CSI cameras, so if you do have a production module, there are carrier boards out there designed for multiple, high performance, CSI cameras.

The hardware layout is a USB2/USB3 pair with a 4-port hub. You can reach 5Gbps in total if the devices are USB3. For USB2 devices, the total bandwidth is 480Mbps. We have seen bandwidth issues in running DeepStream SDK with four USB2 cameras:

For hardware design of Jetson Nano module/developer kit, please refer to product design guide. You can get documents in download center.