Why does my netbook have more USB controllers than ports?

Question

My netbook has three USB ports, but when I look in the device manager:

Five are listed. Does this matter in the least (or, why are five listed)? The reason I bring this up:

See, if I know that two of the devices in the device manager don't actually have physical ports, I can disable then and up that percentage on the other three, correct? I'm constantly being told that my devices can perform faster if I connect them to a USB 2.0 port, but this netbook is less than a year old.

Thanks.

Answer 1

It's common these days for devices to use USB for internal device interconnects; think of it as using USB instead of PCI as its system bus.

Answer 2

Some of those might be for internal devices. Without knowing specifically what's in your netbook, it's conjecture, but you may find if you disable them things will quit working (like say, webcams or card slots). Even if you do disable them, you're unlikely to see a substantial increase in performance on anything on the other ports unless you're already maxing out the throughput on the bus which is fairly unlikely with anything other than a full-blown hard drive.

EDIT: That "your devices can perform faster" message generally means either A: Exactly what it says (but I doubt any new devices have 1.0 or 1.1 ports) or B: It's a powered device that isn't getting enough power, like say a hard drive that you don't have the AC adapter plugged into. EDIT: Or see @AndrejaKo's suggestion of updating chipset drivers (although they SHOULD have worked out of the box.)

Answer 3

You can identify which host controllers are connected to devices by changing the Device Manager to "View devices by connection" in its View menu.

"Tell me if my device can perform faster" should only affect devices that are USB hi-speed capable, but connected to a port (perhaps through a USB 1.x hub) that is only USB Full speed. Note that USB 2.0 requires that a compliant hub be hi-speed capable.

If you are seeing those warnings regularly, then you have hi-speed devices that are connected in a way that limits their bandwidth. Enabling or disabling the USB Host devices will have no effect on that issue, except that disabling a host that is connected to such a device will both stop the warning and prevent the device from being used.

As others have said, it is quite common to use USB as the on-board interconnect even for the keyboard and track-pad that would classically have been connected via an internal PS2 port or something similar. You'll also see the audio devices on the internal USB occasionally.

Answer 4

A number of the devices within your computuer will be connected via USB, such as webcam, possibly wifi, maybe a card reader, etc. USB isn't all about external connections these days.

Answer 5

Just to focus on the other part of the question, make sure that you have newest chipset drivers installed and that your BIOS settings are fine. There is simply no way that your netbook could have shipped with USB 1.1 ports.

Also, what you see there is System reserved bandwidth. It is there to allow system to control other devices and you can't move it from one controller to another. You also can't move used bandwidth from one controller to another because they control different ports and devices are only going to use bandwidth from the port they are actually connected to.

Answer 6

Yet another reason: Ever since USB 2.0 came out, a single "controller" is actually at least two controllers, one for the USB 1.1 mode and one for 2.0 mode. For compatibility reasons, the thing has to come up first in 1.1 mode, then it also offers the 2.0 mode. But the 1.1 mode has to stay available to service 1.1 and 1.0 devices. The one that's called either "Universal Host Controller" (Intel chipset) or "Open Host Controller" (anyone else's) is the 1.1, and the "Enhanced Host Controller" is the 2.0. With 3.0 it's the "eXtensible Host Controller"...