I found that passing
-draftmode to pdflatex does not change the compile time of my document (~10 minutes) at all, while passing
graphicx reduces it to about 1 minute. From the documentation I thought that
-draftmode should have the same effect when the long compile time is caused by a lot of figures (mine are mostly in pdf format).
-draftmode doesn't yield a pdf I cannot check if the graphics are included or not.
-draftmode Sets \pdfdraftmode so pdfTeX doesn't write a PDF and doesn't read any included images, thus speeding up execution.
"doesn't read any included images" sounds to me quite similar to what
draft does with
edit 2: the culprit turned out not to be the figures but the version of
microtype shipped with TeX Live 2012. With microtype 2.5 from ctan compilation times goes down from 10 minutes to 90 seconds.
$ pdflatex --version pdfTeX 3.1415926-2.4-1.40.13 (TeX Live 2012/Debian) kpathsea version 6.1.0 Copyright 2012 Peter Breitenlohner (eTeX)/Han The Thanh (pdfTeX). There is NO warranty. Redistribution of this software is covered by the terms of both the pdfTeX copyright and the Lesser GNU General Public License. For more information about these matters, see the file named COPYING and the pdfTeX source. Primary author of pdfTeX: Peter Breitenlohner (eTeX)/Han The Thanh (pdfTeX). Compiled with libpng 1.2.46; using libpng 1.2.46 Compiled with zlib 184.108.40.206; using zlib 220.127.116.11 Compiled with poppler version 0.18.4