Re: Precompiled headers do not speed compilation up?

[Andre Poenitz]

Markus Dehmann <markus.dehmann@gmail.com> wrote:
> I include lots of header files in my code, so compilation is very
> slow. I tried speeding it up by using precompiled headers, but that
> didn't speed it up at all. Does anyone know why, or have the same
> experience?

Same experience about a year ago in a ~200kLOC OS project, organized 
in ~10 sub directorys with files with an average of 500 lines leading
on average to compilation units in the range of 50...100 kLOC.

Using pch for std includes and a bit of boost took about 10% longer then not
using it. As the whole project was too slow to compile less "orthodox"
methods like combining source files were (successfully) used.
 
> [...] Why would precompiling the header not help in this situation?
> Am I doing it wrong?

Probably nothing. There seem just to be environments were (some) g++'s pch 
don't work well. (And note that I can't comment on very recent g++...)

Andre'