"Doug Ellice" <> wrote in message
news:Z5ydnfLhTOHeJDLcRVn-...
> n0sferatu wrote:
> > When I connect my IPod (latest gen) to my Thinkpad T40 (which I KNOW has
> > USB2.0 ports) (running Win 2003), I get the above message.
> >
> > When I look at Device Manager and list connections by type, I see many
USB
> > Hubs, and one USB Enhanced 2.0 Hub; the IPod is connected to one of the
> > other ones.
>
>
> I think this might be Windows lying to us.
>
> I have a similar problem. I connected a no-name powered USB hub to my
> Dell desktop. I constantly get pop-up messages announcing that this
> USB-2 device would work faster if it were connected to a high-speed port.
>
> My computer doesn't have any USB-1 ports, I don't think.
>
Yes it does.
> When I click on the pop-up balloon, as invited, for more info, I also
> see a chart listing many USB ports. Like yours, only one of my 8 is
> listed as high-speed.
>
The OHCI (USB1) ports are listed first (usually 2 ports to a root hub)
The EHCI (USB 2) port is the last one (usually as many ports as all the
above together.)
> I'm convinced this is a Windows XP problem of some sort, and I ignore it.
>
> Does your iPod work O.K. when you connect it, despite the pop-up "error"
> message?
>
Is this no-name hub of which you speak a true USB2 hub? Unfortunately,
because the USB2 specification contains an ambiguity, hub, peripheral and
motherboard manufacturers are able to sell devices as USB2 devices but that
do not support the 480 Mbps high speed mode.
Some devices are occasionally encountered which require a USB2 specific
driver to be loaded otherwise they default to USB1. I have no knowledge if
the iPod is one of these devices.
This effect can also be seen if the USB cable that you use is not up to
performing at USB2 speeds (or is too long). This could also be true of a
true USB2 hub that has marginal performance. If the data is sufficiently
corrupt, the USB system down trains to USB1 speeds.
I have also encountered the occasional device that works in one port, but
not in another. Try plugging into a different port.
HTH
Ian.
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