USB root hubs

By GreatLife ·

I am looking out for an answer from quite a long time. I posted it on wiki-answers too. But didn't get a reply so far from anybody. Hope I could get some responses here in this forum. The question is: "How many USB root hub entries would I find in Device manager (Win XP) if I have 4 USB ports on the PC". Given 'n' USB ports what would be the number of entries in Device Manager. I ask this because - the number of USB root hub entries are different from the number of USB ports on the computer.

Awaiting responses.

Thanks !!

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by IC-IT In reply to USB root hubs

You would find at least two, but this depends on the board architecture, it could be only one. But usually an internal hub will have 2 ports assigned to it.
Exactly why do you need (or want) to know?
In Device Manager you can check the hubs properties to determine the devices attached (or empty port) and the power consumption.

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by GreatLife In reply to Likely

Ok. Let me give you an example. I have six usb ports in all on my system. 2 in the front and 4 at the back. Now if I go into device manager and check under "Universal Serial Bus Controller" I have the following:-

Intel(R) 82801 GB Universal Host Controller - 27C8

Intel(R) 82801 GB Universal Host Controller - 27C9

Intel(R) 82801 GB Universal Host Controller - 27CA

Intel(R) 82801 GB Universal Host Controller - 27CB

Intel(R) 82801 GB Universal Host Controller - 27CC

USB root hub
USB root hub
USB root hub
USB root hub
USB root hub

Now though I have physically 6 USB ports, I just see 5 USB controllers and 5 USB root hubs. Why so? Shouldn't there be 6 of those?

I hope this is clear now. Thanks for your help.


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Mine is similiar

by IC-IT In reply to usb

However the last Controller entry reads "enhanced" as in;
Intel(R) 82801FB/FBM USB2 Enhanced Host Controller - 265C
I have 8 ports which discounting the "master" 2.0 controller/hub balances out to two per hub. Your motherboard may have a set of pins to allow additional devices (2) or they may have chosen not to wire it.
You may want to check and see if you have USB 2.0 enabled. This site and the listed utility can help.

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