Generic questions just get generic answers! If you want to get useful help, post your code or at least a description of the process you follow to normalize the keys.

Without context it is difficult to say, but 40 operations/seconds doesn't look very impressive unless you are performing quite complex operations.

Profilers (as Devel::NYTProf) can be very helpful for finding hot spots in your program, but they tend to make you focus on small scopes that only will give you relatively small speed increases (typically < 30%).

If you want to improve the speed of your program by orders of magnitude your first action should be to examine the algorithms you are using and to try to replace them with better ones.