c:\test>942747.pl Rate hash comma array packed hash 186995/s -- -27% -76% -77% comma 255572/s 37% -- -68% -69% array 789101/s 322% 209% -- -4% packed 819141/s 338% 221% 4% -- Rate comma packed hash array comma 273531/s -- -62% -70% -86% packed 714529/s 161% -- -21% -63% hash 900220/s 229% 26% -- -53% array 1925183/s 604% 169% 114% --