If you want to make your code faster you need to know where it's spending the most time. To do that, use a profiler. Normally I would suggest you start with Devel::DProf but since you don't have a lot of subroutines it won't be much help. Instead something like Devel::SmallProf might be better, since it's line-oriented.

Once you've identified the slow parts of your code you can work on a solution. You'll be able to post more focused questions which are more likely to get answers here.

-sam