Optimization beyond the Module Border

Hi all, I have noticed that there is a great difference between optimizing modules separately and all at once, e.g., with -fforce-recomp. I have had examples factors up to 15 in run time (and even different behavior in context with unsafePerformIO). Is there any option that makes ghc write out that intermediate optimization data he seems to use in order to get the same efficiency in a module-wise compilation? Greetings Bernd