iMac USB Hi-Speed Bus vs SuperSpeed Bus

[Solomani]

I was wondering if someone can help explain the following to me.

Looking at my late-2012 iMac (21.5" quad-core i7) System Information, the hardware lists 4 USB ports in the following order:

USB 3.0 Hi-Speed Bus
USB 3.0 SuperSpeed Bus
USB Hi-Speed Bus
USB Hi-Speed Bus

My first question is, does the hardware system info above imply that I have two USB 3.0 ports and the other two are older USB 2.0 ports? I wasn't aware that Apple mixed and matched USB ports.

And what is the difference between a USB 3.0 Hi-Speed Bus and a USB 3.0 SuperSpeed Bus? Is one better than the other?

Just some USB questions that I never really paid attention to before. Maybe it might make a difference if I knew which is the best iMac USB ports to plug in something (like charging my iPod Touch or iPad or synching via USB).

 

[Bear]

Superspeed is 5.0 Gbit/s
HiSpeed is 480 Mbit/s

The one that says USB 3.0 Hi Speed Bus probably means it sees a USB 3 controller in a slower device. The ones that just say USB Hi-Speed Bus probably have USB 2 devices connected.

If you list what's connected to each port, you might get a better answer.

 

[Solomani]

Superspeed is 5.0 Gbit/s
HiSpeed is 480 Mbit/s

The one that says USB 3.0 Hi Speed Bus probably means it sees a USB 3 controller in a slower device. The ones that just say USB Hi-Speed Bus probably have USB 2 devices connected.

That's only partially true. When I listed the above hardware profile, I only had a single USB device attached, which was an Apple Extended USB Aluminum Keyboard (using the USB 2.0 specification) attached to USB port #4, which is one of the USB Hi-Speed Bus ports.

The other 3 ports have nothing plugged into them. Very odd.

 

[Bear]

That's only partially true. When I listed the above hardware profile, I only had a single USB device attached, which was an Apple Extended USB Aluminum Keyboard (using the USB 2.0 specification) attached to USB port #4, which is one of the USB Hi-Speed Bus ports.

The other 3 ports have nothing plugged into them. Very odd.

I forgot how OS X lists USB devices. (I haven't had to check System Information on my system in quite a long time.) I'd have to see a listing with devices plugged in to give an accurate answer, possibly from more than one configuration of devices.

 

[DeltaMac]

I think you can test this.
Connect a USB 3.0, SuperSpeed device to one of the built-in ports, then refresh the USB page of System Information.
What does that page report for the SuperSpeed connection?
Eject the device, and move the USB to another port, then refresh the page to update the list. What do you see now?
Do the same for each of the ports.
Now, if you have them available, connect true USB 3.0 devices to all ports at the same time, then refresh the page again. (you can't do this with a USB keyboard, obviously, unless the keyboard is a USB 3 model, I don't know if those exist yet)
Are ALL ports showing as SuperSpeed devices?

I think you will find out that the connection speed is determined by the device connected to the port, and not the port itself (your Mac doesn't know what you will connect prior to the connection, only after.)