The actual USB spec (available here - http://www.usb.org/developers/docs/) calls
for a front panel usb cable length of no more than 10 inches.  This assumes a
five inch copper trace from the southbridge to the connector and a one inch
trace on the front panel daughterboard. 

Many (most?) cases exceed this limit.

Cheers,
Andrew




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---- On Mon, 13 Apr 2009, Xiaofan Chen (xiaofanc@gmail.com) wrote:

On Mon, Apr 13, 2009 at 5:11 AM, John Ferrell  wrote:
> While working on another project (Video Capture Device not working) I
> stumbled across a note that stated that all USB ports are not equal.
> Frequently for whatever reason those that come out to the front of the
> case are not as robust as the rear connectors.

Yeah that is true. I think this is related to the following fact.
All the connectors are most likely from the south bridge
(except when you are using the PCI USB card).
The rear connectors usually come directly from the
motherboard or through short cables. The front connectors
usually come to the front through longer cables. Some of
the front connectors are of inferior workmanship as well.

Xiaofan
My Blog: http://mcuee.blogspot.com
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