[CUBE] Slow USB camera

[Arturo Pérez]

On Friday, December 20, 2002, at 07:58  PM, Bill Bradford wrote:

> On Fri, Dec 20, 2002 at 12:18:39PM -0500, ACS wrote:
>> That's bizarre...I downloaded the contents of a full 128 MB card
>> through the USB camera interface, in less than 4 minutes. What kind of
>> camera are you talking about? Mine is a Canon Powershot G2.
>
> USB 1.0 should theoretically do a little over 1 megabyte/sec (its a 
> what, 11
> or 12-megabit connection?).
>
That's all that the 11 megaBIT/second rating is: theoretical.  With 
protocol
overhead and poor device drivers and a whole bunch of other factors I'm 
sure
that the real throughput is a lot less.  I'm sure that the port on the
camera is a blazing fast 230Kb/s serial port that can pretend to be a 
USB port.

Check this out:

http://www.robgalbraith.com/diginews/2000-07/2000_07_20_fw_reader.html

The unity looks exactly like my Lexar.  The best USB device on that 
page gets
about 0.8MB/s.  The Unity gets 2.2MB/s.

Please don't try and "diagnose" what's wrong with my camera, software 
etc.  I
don't perceive a problem and I was just volunteering information.