bench.forth

: factorial ( n -- n! | err:1024 )
    dup 0< if drop 1024 throw then
    dup 0= if
        drop 1
    else
        dup 1= if
          drop 1
        else
          dup 1- factorial *
        then
    then ;

: bench ( ntimes -- sec )
    time swap
    0 do 10 factorial drop loop
    time swap - ;

10000000 bench . \\ takes 2-3 seconds on Intel(R) Xeon(R) CPU X5650  @ 2.67GHz

######################################################################

def factorial(n):
  if n < 0: raise RuntimeException('neg')
  if n == 0:
    return 1
  else:
    if n == 1:
      return 1
    else:
      return n * factorial(n-1)
      
import time
def bench(n):
  s = time.time()
  for i in range(n): factorial(10)
  print time.time() - s

bench(10000000) # takes about 21 seconds on Intel(R) Xeon(R) CPU X5650  @ 2.67GHz using Python 2.7.3