Last time I checked somebody working on modules said something along the lines of "don't expect modules to speed things up". The goals were different, apparently (stop #defines from leaking everywhere, large-project management, libraries). Has this changed, are there any benchmarks available?
If its true that speeding up compilation was not a goal then the committee is out of its mind. Speeding up compilation would have more impact on productivity and the environment than almost anything else that could be done with the language.
The committee was always out of the mind. In the past years they have neglected compile times, debug build performance, error messages or sometimes even performance.
Modules contain an optimization (less include leaking) and a pessimization (more serialized build graph). Only the former applies to CPU time, so modules should lead to less cpu time, but it's unclear exactly how that translates to wall time.
