We're converting quite a large Flex project from a monolithic web application project type to multiple projects where most of the existing files (~2000) will newly live under a Library project and there will be multiple runnable projects beside it (like web version and a desktop version).
What concerns us is the compilation time. It used to be something like a minute (already more that we would have liked) but now it easily takes ~10 minutes which is unacceptable.
Is it expected to see such a big difference when moving from MXMLC compiler to COMPC? I know MXMLC optimizes its usage and will skip files that are not used in the application it is expected that the COMPC build would be slightly slower as it compiles more files but I don't think the difference should be 10 fold, should it?
The only thing I can think of that would account for such a discrepancy is if you have a lot of dead code in your project. When building an application, only the needed classes are compiled. This is not the case for library projects. It does take a little longer to compile multiple library projects rather than one monolithic one (assuming the same class coverage), but certainly not to the extent you describe.
There is some "dead code" for sure but not 10x as much as the production code so there must be some other factors plaing role.