My laptop's model number is an ASUS X205TA-SATM0404G. It has 2 USB 2.0 ports, which I have verified by looking up the specs online and also via the software and techniques mentioned here: How to detect if a USB port is 3.0 or 2.0?

So, why is it that in Device Manager, under "Universal Serial Bus controllers", there is an entry that reads "Intel(R) USB 3.0 eXtensible Host Controller - 0100 (Microsoft)"? To give more info, this is the list of entries:

Universal Serial Bus controllers
   Generic USB Hub
   Intel(R) USB 3.0 eXtensible Host Controller - 0100 (Microsoft)
   USB Composite Device
   USB Root Hub (xHCI)

My operating system is Windows 8.1, 32 bit.

  • The chip (not sure what they use on that model to control usb) supports usb 3 but the manufacturer did not design that notebook to make use of it, so the driver installer only looks at the chip as supporting 3.0 and installs the driver for it even though you can never use it. – Moab May 1 '16 at 1:10

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

To see which speed ports support, 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

So the USB chip supports USB 3.0, but the OEM on the Tabled used micro USB 2.0 port.


Intel Atom processors are a SoC or system on a chip. Which means they put everything including the kitchen sink onboard the CPU. So there is often devices on these smaller netbooks not utilized.

On my ASUS X205TA not only do I have a USB3.0 controller that shows up but in not broken out there is also a hardware com1 port.

If you look at the datasheet for the Intel Atom Z3735F processor in these both devices likely exist on the CPU chip itself, USB for sure and serial port more than likely. Its not that "OEMs are indeed stupid and use USB 3.0 controllers, but use 2.0 ports." Its more often that the engineers had a price point and a feature list they were given. They just did not utilize it for cost or space considerations.

Intel is not going to make 8 versions of a CPU with different configurations. Often there are unused devices that are not used integrated into various chips and components in most electronics (not just computers). To make things less confusing unused features usually have a way to be turned off via grounding pins or permanently set firmware/BIOS options. Sometimes manufactures don't do it, can't do it, or planned to have that feature and it gets hastily taken off to save space or cost at the last minute.

One common example of this is most newer i3/i5/i7 Intel processors support up to 4 monitors while many motherboards only have 1 monitor connector. It is becoming more common for motherboards with integrated graphics to have 2 and sometimes 3 monitor connectors but there still are not that many motherboards that break out all 4 display ports.

What you're seeing is common with newer hardware at all levels.

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