[sane-devel] Scanning speed slower, or is it just me?

[Jeremy L Rosenberger]

Greetings,

This may not be a particularly useful e-mail since it will be a little
short on specifics, but hopefully it may provide enough information to
give someone (with more knowledge of SANE internals than I have) an idea
of what might be going on.

Once upon a time, I used my Microtek X6 USB with Windows 2000 and with
SANE on Linux. The performance under both was about equal. This was on a
750MHz Athlon system with a VIA chipset using some variant of the 2.4
kernel.

Then, somewhere along the line of 2.4 kernel versions (using the uhci,
or "alternate" UHCI driver) and SANE versions, things stopped working:
The scanner lamp would turn on and move about an inch before "hanging."
I can't recall whether this locked up the machine or not. Unfortunately
I don't know whether this problem was ever resolved, because I stopped
using said Athlon system and now pretty much exclusively use my laptop,
which is a 700MHz Pentium III.

Now on my laptop (still using the "alternate" uhci kernel driver),
scanning works but is much slower than it was before. (Of course this
could be due to the new hardware, but there is near parity in the two
machines' capabilities.) I tried a couple of color scans at 200dpi and
300dpi, and the scanner head will move about an inch, pause for a few
seconds, move another inch, pause, and so on. (Before, the motion was
pretty much continuous.) It's as if the scanner is producing data too
quickly and has to wait for the computer to catch up (although this
doesn't seem very likely).

I'd be happy to do additional testing and provide more data, if someone
would tell me what sort of data (perhaps turn on debugging somewhere and
send log output?) would be interesting.

Of course, I am glad that even though it's slow, it works! :-)

Cheers,
Jeremy

-- 

Jeremy L. Rosenberger * jlr4 at cornell.edu
http://home.frii.com/~jeremy/