These are fairly typical results. Obviously the exact times you get are dependent on your computer processor's speed, and how busy it is at the time... [tai@miranda (pts/0) faster]$ time perl base37.pl < faster-data.txt > /dev/null 26.645u 0.066s 0:27.63 96.6% 0+0k 13680+0io 0pf+0w [tai@miranda (pts/0) faster]$ time perl bitshifting.pl < faster-data.txt > /dev/null 22.155u 0.083s 0:22.58 98.4% 0+0k 0+0io 0pf+0w [tai@miranda (pts/0) faster]$ time perl mult.pl < faster-data.txt > /dev/null 27.857u 0.101s 0:28.22 99.0% 0+0k 0+0io 0pf+0w [tai@miranda (pts/0) faster]$ time perl xs-version.pl < faster-data.txt > /dev/null 95.109u 0.312s 1:38.24 97.1% 0+0k 1288+0io 2pf+0w