8 seconds for that much work sounds pretty good to me. However..

The /o option compiles a regular expression -- it tells the Perl compiler that the regexp is invariant (er, won't change during the life of the script). That saves some time. Have you benchmarked your script with and without that option?

If Perl still isn't fast enough, I suppose rewriting your script in either C or assembler is your only hope (assuming that you are already running on the hairiest machine you can get).

--t. alex

"Nyahhh (munch, munch) What's up, Doc?" --Bugs Bunny

Update Thanks to crazyinsomniac for the reminder that the /o option is buggy for some versions of Perl 5.6.