map vs mapMultiprocessing

mapMultiprocessing.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
import multiprocessing
from datetime import datetime
def f(x):
    n = int(1e2)
    for i in range(n):
        for i in range(n):
            # computo
            i
    return i*i

def main():
    n = int(1e5)
    np =  multiprocessing.cpu_count()
    pool = multiprocessing.Pool(processes=np)
    l = range(n)
    t0 = datetime.now()
    map(f,l)
    print datetime.now() - t0

    t0 = datetime.now()
    pool.map(f,l)
    print datetime.now() - t0

if __name__ == "__main__":
    main()