2015/06/22 14:04:56
jeffledge
Ok, so i have 4 usb ports on the back of my desktop and two on the bottom front however i have NO CLUE which ones are the USB enhanced ports. the device manager shows i have two of them. How do i know which ones are the enhanced????
 
2015/06/22 16:26:10
kevinwal
jeffledge
Ok, so i have 4 usb ports on the back of my desktop and two on the bottom front however i have NO CLUE which ones are the USB enhanced ports. the device manager shows i have two of them. How do i know which ones are the enhanced????
 



Yeah, it's kind of confusing how this works. As I understand it, the enhanced USB host controller is a device driver and not a physical device. There are in fact several USB host controllers and Windows will delegate device control to the correct controller based on the speed of the device.
 
This is how it works: A device plugged into an enhanced port will use the enhanced host controller directly regardless of the device's speed. If it's plugged into any other USB 2.0 port and it is a high speed device, Windows will route the connection through the enhanced host controller because of the device's speed capabilities. The bottom line is that it shouldn't matter what port you plug a device into, it should just work.
 
Here's a snippet from the USB FAQ at https://msdn.microsoft.com/en-us/library/windows/hardware/dn423379(v=vs.85).aspx
 
 
If the USB 2.0 port is connected to an EHCI controller through a USB 2.0 hub, the traffic moves through the EHCI controller, and the USB 2.0 driver stack is loaded ...
 
If the PC's USB 2.0 ports use a companion controller, the host controller to which the port is routed depends on device speed. For example, a low speed device connects through a UHCI or an OHCI controller, and uses the USBUHCI or USBOHCI driver. The PC routes a high speed device to an EHCI controller, therefore, Windows uses the USBEHCI driver.
Different device speeds do not determine the driver that is loaded for the controller. However, different device speeds might determine which controller is used. The controller always uses the same driver.
2015/06/22 16:26:58
BobF
If you don't have an owner's manual, plug a USB device into them and look in Device Manager.  Select view by connection and it should be easy to track down
2015/06/25 11:52:13
BassDaddy
BobF
If you don't have an owner's manual, plug a USB device into them and look in Device Manager.  Select view by connection and it should be easy to track down


Thanks Bon, that's one I can use. Great tip.
2015/06/25 14:09:11
Sycraft
The program USB Device Tree Viewer, which is a free download, will also enumerate all USB devices and show what is hooked to what. Works pretty well in my experience.

2015/06/25 15:19:44
BobF
I also just found a tool, USBView in the Windows Debug toolkit
 
Still, Device Manager is something everybody has already ...
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