[sane-devel] Bad Performance uhci (vs. usb-ohci ,ohci)

Gunther Mayer Gunther.Mayer at t-online.de
Sun Feb 10 10:10:07 GMT 2002


Hi,
the "uhci" module suffers from very bad performance (linux-2.4.17).

Scanning 150dpi A4 (merlin670 for Canon N670U over libusb-0.1.4) gives:
  uhci:    135 sec.
  usb-uhci: 43 sec.
  ohci:     35 sec

This corresponds to about 50K/sec for 'uhci' (and the scanner must stop'n'start) !

Is this a known bug in "uhci" ?

Are there plans to resolve the situation to have 2 modules,
probably each with it's own bugs?

First, it would help to have a list with user-visible differences.

Regards, Gunther



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