Re: Guidance on USB Contoller listing in Device Manager, please
- From: Ron <Ron@xxxxxxxxxxxxxxxxxxxxxxxxx>
- Date: Tue, 27 Mar 2007 17:11:15 -0700
Sure, but when I got the PC the motherboard based USB ports were V2.0.
Somewhere along the way they changed to 1.x. I had added a USB PCI card and
those ports work under V2 just fine. Once I figured that out I rejacked
everything so the mobo based ports only get slow devices like the mouse, but
I'd be a lot happier of the mobo ports worked at the correct speed.
"Uwe Sieber" wrote:
.
With USB 2.0 printed on the package devices just sell better.
As long as they doesn't write "USB 2.0 highspeed" it just
means that it works with USB 2.0.
For a printer USB 2.0 full speed is good enough. Fewer problems
with USB switches or long thin extension cables :-)
Uwe
x-eyed-bear wrote:
Thanks for this clarification.
I do not understand however why a known USB 2.0 device (my HP 8450
printer) is shown (in SiSoft Sandra) as being connected to a 1.1 Host
Controller and shown as having a connection running at 12 Mbps ("Full"
speed) when it should be shown connected to the Enhanced controller and
connected at (up to) 480 Mbps ("High" speed).
Uwe Sieber wrote:
An USB host controller and an USB root hub is the same
hardware device. The host controller is the logical device
at the PCI bus side while the USB root hub is the logical
USB side which provides USB ports. It's all hardware
which needs software (drivers) to be used.
An USB2 controller has two logical 'incarnations', one for
USB2 and some for USB1. It depends on the attached device
which incarnation is used. The USB1 incarnations are usually
splitted, so each incarnation ususally has two ports.
Microsoft UVCView shows it:
http://www.microsoft.com/whdc/device/stream/vidcap/UVCView.mspx
With this tool you will see that the number of USB2 and USB1 ports
is equal because they are identical physical ports.
Uwe
x-eyed-bear wrote:
I'm one of the thousands of users who has the dreaded 'USB Device not
recognized' error. I don't want to burden this forum (yet) but asking
for help on that one. I'm trying to solve it myself by better
understanding how USB devices are handled by Windows XP (SP2, that
is). I need some guidance on understanding the meaning and
significance of the 'USB Controller' section of the Device Manager
window.
On my system (ASUS A8V motherboard with 6 out of a possible 8 USB
ports installed) the listing shows:
'USB Root Hub' (4 times)
'VIA Universal Host Controller' (3 times)
'VIA USB Enhanced Host Controller' (once)
Loads of newbie Questions:
1. What is a Hub and what is a Root Hub? Are they hardware, microcode
or software?
2. What is a USB port and how does it differ to a hub?
3. What is a Host Controller? Is it hardware, microcode or software?
4. I am right in assuming an Enhanced Host Controller is one which
provides USB 2.0 support, the others being USB 1.1 only?
5. Why does the output from SiSoft Sandra show no devices attached to
any of the 6 ports on the Enhanced Host Controller, but does show the
expected devices connected to either Port 1 or Port 2 on one of the
three Universal Host Controllers?
6. Why have I got 3 of these host controllers and not just 1 like the
Enhanced Host Controller?
7. What is 'Enumeration' and why would a device connected to a USB
port fail this process?
8. Is the driver that is listed in the properties for a Hub or Host
Controller part of Windows XP, or a specific piece of software
supplied with the device?
9. Why do some device have no such driver (for example the Nikon D80
DSLR camera which Windows XP will not recognise - but only on this
computer)?
Finally, why do so many people report a 'USB Device Not recognized'
error, across such a wide range of systems and devices, across so
many years, without a definitive solution being developed by the
industry? Microsoft's absence from the this scene is a disgrace. The
cost to users must run into 10's of thousands of man hours by now.
There are thousands of pages of guidance on the internet which range
from the incredible to the insightful - many of them contradicting
others. None of them have solved my specific example (but I've only
been trying to solve this for 2 weeks ....). If we had this sort of
problem with our cars, telephones, TVs, etc, it would have been the
subject of incisive media analysis. Why do we let the computer
industry get away with this situation? Nikon's technical support
response to the problem could form the script for a Broadway comedy;
it includes re-installing XP. Who is going to pay for that?
- References:
- Guidance on USB Contoller listing in Device Manager, please
- From: x-eyed-bear
- Re: Guidance on USB Contoller listing in Device Manager, please
- From: Uwe Sieber
- Re: Guidance on USB Contoller listing in Device Manager, please
- From: x-eyed-bear
- Guidance on USB Contoller listing in Device Manager, please
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