$ sudo bash -c "echo 1 >/proc/sys/vm/drop_caches"
$ time wc lesms10_big.txt 
 14152200 113528600 652751200 lesms10_big.txt

real 0m3.412s
user 0m3.307s
sys  0m0.097s

$ sudo bash -c "echo 1 >/proc/sys/vm/drop_caches"
$ time ./wc.pl lesms10_big.txt
 14152200 113528600 652751200 lesms10_big.txt

real 0m0.613s  (5.57x)
user 0m4.168s
sys  0m0.432s