Hi,
Our department recently installed Ubuntu and AMC on some desktop pc's, to help those in charge of large section exams to process them. Recently, the faculty member with one of the ubuntu boxes told me that it took 6 hours to print 1100 papers for his most recent exam. This was not in line with my experience, so I investigated why. I discovered that there are three different programs you can use to split out the individual tests. I don't know how long this option has been around, but I've been using AMC (on a mac) since 1.2.1 (these are at 1.4) and the default has always been pdftk. Since that worked, I don't know when the other options showed up. On the new Ubuntu boxes, with a clean install of AMC 1.4, qpdf is the default. I was wondering why people use qpdf instead of pdftk. Just to illustrate my point, I did some (admittedly rough) timings of each program in printing 10 exams. Note that these were not sent directly to the printer because we are still having some issues with the printer and these boxes. Rather, they were printed to files. The timings are:

qpdf 201 sec.
pdftk 27 sec.
gs 23 sec.
Under these timings, printing 1100 exams under qpdf takes 6.14 hours, which is in line with my colleagues experience. On the other hand, pdftk takes .8 hour and gs takes .7 hour.

qpdf is so much slower than the other options that I was wondering what the use case was? Is it a backup option, in case pdftk has problems (and we know it has occasionally)? Is there a use case where qpdf is faster?

I apologize for all the questions. I switched my colleagues machine to use pdftk, when solves his problem. I'm just curious however.

Thanks,