fScanX

Scanning Throughput

The fi-4120C has a USB 1.1 interface, while the fi-4120C2 has USB 2.0. The C2 has significant performance advantages for grayscale, color, and duplex scanning. For single-sided monochrome scanning the two models are equivalent.

The following tables show the actual times required to scan 10 pages. The tests were all run on a dual 2.5gHz G5 with 2.5GB of RAM. All times are in minutes and seconds.

Monochrome
single-sidedduplex
dpi fi-4120C fi-4120C2 fi-5650C fi-4120C fi-4120C2 fi-5650C
200 00:24 00:25 00:15 00:47 00:26 00:17
300 00:35 00:35 00:15 01:09 00:37 00:16
400 01:07 01:07 00:18 02:16 01:10 00:24
600 01:07 01:08 00:40 02:14 01:54 01:17

Grayscale
single-sidedduplex
dpi fi-4120C fi-4120C2 fi-5650C fi-4120C fi-4120C2 fi-5650C
200 00:51 00:25 00:15 01:40 00:27 00:16
300 01:54 00:37 00:17 03:44 00:40 00:33
400 03:17 01:10 00:36 06:29 01:13 01:10
600 07:10 01:39 01:32 14:09 02:31 02:58

Color
single-sidedduplex
dpi fi-4120C fi-4120C2 fi-5650C fi-4120C fi-4120C2 fi-5650C
200 02:34 00:40 00:15 05:02 00:51 00:25
300 05:29 00:51 00:32 10:50 01:22 01:01
400 09:39 02:16 00:54 19:05 03:08 01:46
600 21:17 03:19 02:06 42:10 05:47 06:07

CPU & RAM

The monochrome scans took ~5% of a single CPU, so even much slower machines should show essentially the same performance. Monochrome scanning uses a maximum of ~9MB of RAM for buffering image data during scanning, so even machines without much RAM installed should show no RAM-related performance problems.

The grayscale and color scans took most of the processing power of a single CPU, indicating that slower machines should be expected to show slower performance. This is for the 4120C2 on USB 2; for the 4120C I expect that the USB 1.1 connection will the limiting factor for any G4 and maybe even some G3s.

Grayscale scanning uses a maximum of ~64MB of RAM for buffering image data during scanning, so a machine with constrained memory might see lowered performance. Color scanning can use a maximum of ~192MB RAM for buffering image data during scanning, so memory is very important for color scanning. Those buffer sizes are for 600dpi duplex scans; 300dpi will use 1/4 as much; single-sided will use 1/2 as much; 300dpi single-sided will use 1/8 as much. Take into account that if you want to do high-resolution grayscale or color scans, you will need an appropriate amount of RAM in order to fully take advantage of the scanner's performance.

The poorer performance of the 5650C on higher-resolution grayscale and color scans is because that model of scanner can feed paper in landscape mode and gets its highest throughput that way. This means that fScanX has to rotate the scans on the fly as the data comes in, and the current version doesn't keep up at 600dpi. (I could probably have gotten better numbers by running the 600dpi scans in portrait mode, but I'm interested in getting the scanner's full speed, not fudging the numbers.) Even when the software is optimized, the 5650C won't post speeds much higher than the 4120C2 for 600dpi color because the scanner can produce data faster than USB 2 can send it to the Mac.