It seems to me that Perl is not the language for a massive number crunching problem. Why not have Perl parse out the values and then feed a C or FORTRAN subroutine to do the crunching? It might speed it up so much you don't need to go to so much trouble.

I like the idea of just running it at a very low priority. Don't bother with the screensaver; just let it start pulling when the computer has nothing better to do.

—John