USB 2.0 Hub is Culprit of high CPU usage by SYSTEM service - Why?

[Ford Man]

I can now verify that my external USB2.0 hub that I added is what is
causing my "SYSTEM" service to stay pegged at 85% or more CPU
resources! If I remove the hub, CPU usages hovers at 5% or less, like
it used to. When the system service is hogging resources like this,
CD recording apps peg their CPU usage meter, windows open slower, the
hard drive cranks longer while attempting to change folders, etc, etc,
etc. So, at a minimum, the usbhub.sys driver assigned to run my
"Generic USB Hub" does not seem optimized.

On the other hand, when I attach a USB 2.0 "Jumpdrive"
(http://www.lexarmedia.com) drive, I DO get close to the advertised
performance, so performance of the USB2 device itself isn't a problem
for me, just what the USB2 hub does to overall system performance.

This hub was like many (most) hubs that do not come with their own
drivers, but rather uses the built in WinXP(SP1) USB drivers.

So, even though it appeared that the critical updates downloaded
through "Windows Update" were the culprits (since I had installed no
other software), it was instead a piece of hardware that activated a
windows driver, USBHUB.SYS. However this driver is loaded for the
other internal USB hubs, so why is it a problem for an external one?
Is it because it's just a "dumb" hub without a controller, and the
system's internal controller (for the port that the external is hooked
to) is constantly "polling" the hub?

Whatever the cause, this is unacceptable. I now have all the same USB
devices hooked to internal ports without a problem, but my USB 2.0 hub
is sitting in a pile now. I added it to expand my ports and make them
more accessible to the front of the computer.

Why is this happening, and what are the options for different hubs,
etc. to eliminate this problem?

Ford Man

[Peter]

All very interesting because i have not been able to get any where near the
'advertised' speed of USB2 and haven't figured out why..... I have an add-in
pci card with 4 external, 1 internal and although it runs, something is
wrong for certain. Mine does not 'hog' resources the way yours seems to, but
i certainly have my own set of problems with support for USB2 in Windows
XP..
My ports have ONLY a USb2 HD installed...
"Ford Man" > wrote in message
...
>
> I can now verify that my external USB2.0 hub that I added is what is
> causing my "SYSTEM" service to stay pegged at 85% or more CPU
> resources! If I remove the hub, CPU usages hovers at 5% or less, like
> it used to. When the system service is hogging resources like this,
> CD recording apps peg their CPU usage meter, windows open slower, the
> hard drive cranks longer while attempting to change folders, etc, etc,
> etc. So, at a minimum, the usbhub.sys driver assigned to run my
> "Generic USB Hub" does not seem optimized.
>
> On the other hand, when I attach a USB 2.0 "Jumpdrive"
> (http://www.lexarmedia.com) drive, I DO get close to the advertised
> performance, so performance of the USB2 device itself isn't a problem
> for me, just what the USB2 hub does to overall system performance.
>
> This hub was like many (most) hubs that do not come with their own
> drivers, but rather uses the built in WinXP(SP1) USB drivers.
>
> So, even though it appeared that the critical updates downloaded
> through "Windows Update" were the culprits (since I had installed no
> other software), it was instead a piece of hardware that activated a
> windows driver, USBHUB.SYS. However this driver is loaded for the
> other internal USB hubs, so why is it a problem for an external one?
> Is it because it's just a "dumb" hub without a controller, and the
> system's internal controller (for the port that the external is hooked
> to) is constantly "polling" the hub?
>
> Whatever the cause, this is unacceptable. I now have all the same USB
> devices hooked to internal ports without a problem, but my USB 2.0 hub
> is sitting in a pile now. I added it to expand my ports and make them
> more accessible to the front of the computer.
>
> Why is this happening, and what are the options for different hubs,
> etc. to eliminate this problem?
>
> Ford Man