I'm astonished by that time number. I have a 400 page book, with a 150 page answers to exercises that is emmitted as part of the book compilation and then compiled on its own. I use a simple shell script that compiles each twice (for the cross-referencing). It takes perhaps 10 secs on my five year old middle of the road laptop. Are you remaking complex drawings each time? What is the performance sink, I wonder?