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Using a tool to display my computers hardware properties, I can see that my computer has a "USB xHCI Compliant Host Controller".

Does this automatically mean, it is USB 3.0? Or could this also apply to a USB 2.0 connectors?

Jan Rüegg
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2 Answers2

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Yes, you are correct. xHCI means USB 3.0 support (red). USB 2.0 is enhanced host controller (green)

enter image description here

The blue ones are USB 1.1 (OpenHost)

Some OEMs are indeed stupid and use USB 3.0 controllers, but use USB 2.0 ports (micro USB for example).

To see this, run a tool called USB Device Tree Viewer and click on each listed port which has the entry IsUserConnectable (here the user can connect USb devices, some are internally used to attach devices like USB card readers) and look for SupportedUSBProtocols and if the entry Usb300 has a 1 (yes) set. Here not:

enter image description here

magicandre1981
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  • Hmm... what about this: http://superuser.com/questions/1071709/why-does-device-manager-show-intelr-usb-3-0-extensible-host-controller-0100?rq=1 ...? – Jan Rüegg May 24 '16 at 12:06
  • what is your point? – magicandre1981 May 24 '16 at 15:14
  • My point is that in http://superuser.com/questions/1071709/why-does-device-manager-show-intelr-usb-3-0-extensible-host-controller-0100?rq=1 someone also had an xHCI controller, but only USB2 ports. I would like to find out if an xHCI controller means the computer has USB3 ports... – Jan Rüegg May 25 '16 at 07:33
  • xHCI controller measn USB 3.0 CONTROLLER. If the manufacture only uses USB 2.0 (micro usb) it is his fault. Next time ask a proper question, you forget this important part of the question. I'll add this part to the answer *rolleyes* – magicandre1981 May 25 '16 at 16:03
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No, xHCI is designed to work with all speeds of USB devices.

There are devices that has an xHCI host controller but has only USB 2 ports.

On the other hands, on modern motherboards that has both USB 2 and 3 ports, the xHCI host controller is responsible for both types of them. You will also see that even those 12M "full-speed" devices, such as your keyboard and mouse, are attached to it as well. Although often there are fallback EHCI controller(s), I suppose they are for devices that somehow cannot be attached to an xHCI controller (which I have never seen).

In Linux this can been confirmed with lsusb -t or lsusb.py.

P.S. I believe the reason we often (wrongly) consider xHCI = USB3 is because 5Gbps (or 10Gbps) is not supported in EHCI, and xHCI is currently the only/latest standard we have for USB host controllers that supports USB 3.x speeds. But that doesn't mean it is wrong/stupid/impossible for a device to have an xHCI controller but only USB 2 ports.

Tom Yan
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  • @magicandre1981 there's nothing stupid of a manufacturer to have an xHCI host controller (improved standard, better/more updated drivers...) but have only USB 2 ports. It's merely stupid for a user to determine which kind of USB ports a device has by looking up which type of host controller it has. – Tom Yan May 30 '16 at 09:11