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View USB Power and Bandwidth Allocations for a Device

  • Article

Applies To: Windows Server 2008

This topic provides procedures you can use to view the power or bandwidth allocations for universal serial bus (USB) hubs and controllers.

  • View the power allocations for a USB hub

  • View the bandwidth allocations for a USB host controller

Any user account can be used to complete this procedure. However, only members of the Administrators group can make changes to any of the devices or their drivers.

View the power allocations for a USB hub

Hubs for USB devices are self-powered or bus-powered. A self-powered hub has its own power supply and provides maximum power to the device. A bus-powered hub draws its power from the USB to which it is connected and provides minimum power. Devices requiring a lot of power, such as cameras, should be plugged into self-powered hubs.

You can check the power allocations for a USB hub to detect situations in which too many devices are using the hub.

To view the power allocations for a USB hub

  1. Open Device Manager.

  2. Double-click Universal serial bus controllers.

  3. Right-click USB Root Hub (you might have multiple instances), and then click Properties.

  4. On the Power tab, view the power required by each device in the Attached devices list.

Additional considerations

  • Universal serial bus controller only appears if you have a USB port on your computer.

  • The Power tab only appears for USB hubs.

View the bandwidth allocations for a USB host controller

You can view bandwidth only for a USB controller. Some USB devices (for example, modems) might not appear because they do not report bandwidth requirements to the operating system.

Each USB controller has a fixed amount of bandwidth that all attached devices must share. If you suspect a bandwidth shortage for a USB controller, you can confirm this by viewing the bandwidth allocations currently being used by each device.

To view bandwidth allocations for a USB host controller

  1. Open Device Manager.

  2. Double-click Universal serial bus controllers.

  3. Right-click [NameBrand] Host Controller for your system, and then click Properties.

  4. On the Advanced tab, in the Bandwidth-consuming devices list, view the bandwidth used by each device.

Additional considerations

Universal serial bus controllers appears only if you have a USB port on your computer.