I just bought a third PCI USB 2.0 controller, and this one
works in my 2.8GHz Pentium 4 system (which has a P4 Titan ga-8i875
motherboard). This controller that works has an NEC chip and also
has a bunch of decoupling capacitors, including one by every port.
It cost about twice as much as another USB 2.0 controller card
that also use a NEC chip (us$12.50 vs. us$6). The person who
sold it to me seemed to think these capacitors were particularly
important and seemed to think that the quality of these capacitors
was somehow better than another NEC-based controller that was
priced between the two and also had a capacitor next to each
connector.
This new controller really does seem to be connecting
to my av220 USB 2.0 duplex scanner and my USB 2.0 CompactFlash
adapter at 480mbps. With this new controller, my av220 is able able
to scan a letter size page at 300dpi in about 12 seconds, and sysfs
claims that the connections are at 480mbps.
I do not know if the problem with the ports on the motherboard
and controllers using the ALi and VIA chips are triggered by the
different EHCI chips or by analog issues, such as the capacitors.
I am tempted to buy the cheap NEC USB 2.0 controller (without the
capacitors) as well to see if it fails its USB 2.0 initialization.
__ ______________
Adam J. Richter \ /
[EMAIL PROTECTED] | g g d r a s i l
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