Hi James,
Thanks for posting your question here about determining the which devices are connected to which host controllers, I’ll be happy to help.
The easiest way to do this on Window is to start Device Manager and choose View --> Devices by connection.
Then under the PCI bus section you’ll see entries for each USB host controller. Connect a unique usb device like a flash drive to one of the ports and you’ll be able to find which host controller it enumerates on.
I hope this helps!
Let me know if there’s anything else I can do.
Jerome
Plugable Technologies