Simon Matter wrote: >> - The network should be fast enough to keep up with the scanning speed, >> but still the scanner pauses a little between each page - as if it is >>[snip] > > My experience with FI-6x30 is that it seems to have enough memory to do a > duplex scan (at least with 300DPI which is what we are using here) and > keep the whole 2 pages in it's memory. However, the connection to the host > computer is limited by it's USB speed. Connecting the scanner to an old > computer with no high speed USB2 things get very slow. Even with fast USB, > I saw delays between pages with rising scan resolution. I guess that doing > via network adds a little period to it as well. > So, do you see the same delay between pages when scanning for example at > 100DPI with lineart?
Nope, no delays. I can run two scanners simultaneously, scanning 200dpi grayscale in duplex (80 ipm) without any problems at all. The two fi-6130:s are connected to an EeeBox 202 (USB2, gigabit lan). PGM images are about 4MB each. I get what i think is disk flush spikes now and then (very slow disk + filesystem installed on top of NTFS). Because of that, scanning is effectively limited to 140 images per minute when i scan directly on the eee box. When I use saned and the net backend I scan 200dpi grayscale, but it is simplex only, just one scanner, and nothing hits the local slow disk. It *should* be able to scan as fast as the scanner can go... and sending data over the net should only use about 20mbit or so. And if i use both scanners via saned/net at the same time, then the scanning takes exactly the same time as with one scanner only. So obviously it is not a network congestion problem. Something in saned or net backend introduces this small pause between pages... > Also, I don't know how saned works but if it would close the device after > every page you would see a delay for opening it again. You could try > commenting out all unneeded backends in your sane config to make it a bit > faster. > If all doesn't help you may want to strace things to see where it delays. I commented out all backends except fujitsu, but it didn't make any difference... I'll try to look into the saned/net source if i can find some time... Thanks! /Mattias
