[rleigh]

This very much depends upon the project. Have you seen the size of C++ object files with -g3 and lots of template usage? It can swallow tens of gigabytes of disc space only to have the linker elide most of it and give you a library or executable a few megabytes in size. Compared with the size of the inputs, the output is causing a vastly disproportionate amount of disc I/O, and this can end up being limiting, both during compilation and in particular during linking.