On Tue, Sep 18, 2007 at 08:15:25PM -0500, Bo Peng wrote: > > Possible conclusions: Precompiled headers are a waste of time and space. > > 22% increase on compile times, ~300% increase on disk space. > > > > Could somebody please try the same test with a different compiler? > > I tried a while ago with gcc 3.4 on linux. Autotools' pch did not show > any advantage in compile time. This was why I did not add pch to > scons. > > I heard that pch can do magic to msvc though.
I know they work there well. But that basically means that either gcc's pch implementation is poor (actually, the compiles headers is around 30 MB, so it probably reads in 30 MB for each little .cpp file. Even with buffered data that still means traversing 30 MB...) - or, that gcc itself is quick so the pch do not bring any advantage. I am convinced it is not the latter... Andre'
