I reckon this is more comparable to the Ruby version: from random import Random from threading import Thread rand = Random().random THREADS, SIZE = 20,

I reckon this is more comparable to the Ruby version: from random import Random from threading import Thread rand = Random().random THREADS, SIZE = 20, 100000 threads = [] class Test(Thread): def __init__ (self): Thread.__init__(self) def run(self): a = [rand()*SIZE for x in xrange(SIZE)] a.sort() def test(): for i in xrange(THREADS): t = Test() threads.append(t) t.start() for t in threads : if t.isAlive() : t.join() if __name__=='__main__': from timeit import Timer t = Timer("test()", "from __main__ import test") print "%.2f sec/pass" % (t.timeit(number=10)/10) Which results in 5.48 sec/pass Looking at cProfile, 50 or so calls to built-in method acquire takes an avg. 4.102 sec.