Philip Pemberton <piclist@mit.edu> wrote:

> the data throughput is atrocious. Webcam + DSL modem + ICD2 +
> scanner = USB go splat.

Phil:

Going off on a tangent here... But if you have a high-speed (480 
Mbps) USB host, changing your hub may improve device throughput 
dramatically.

All high-speed hubs use a logic block called a Transaction Translator 
(TT) to convert lower-speed USB traffic on the downstream side to 480 
Mbps on teh upstream side. If your hub has only one TT, all of your 
full-speed (12 Mbps) devices are forced to share one 12-Mbps pipe.  
If, on the other hand, your hub has one TT per port, each full-speed 
device gets its own 12-Mbps pipe.

-Andy

=== Andrew Warren -- aiw@cypress.com
=== Principal Design Engineer
=== Cypress Semiconductor Corporation
=== 
=== Opinions expressed above do not
=== necessarily represent those of
=== Cypress Semiconductor Corporation

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