On 9/11/07, Paul Moore <[EMAIL PROTECTED]> wrote: > On 11/09/2007, Nicholas Bastin <[EMAIL PROTECTED]> wrote: > > On 9/11/07, "Martin v. Löwis" <[EMAIL PROTECTED]> wrote: > > > > 3.0: 10 loops, best of 3: 6.76 sec per loop > > > > 2.6: 10 loops, best of 3: 2.61 sec per loop > > > > > > I can't quite reproduce these results. On a 3.2GHz Pentium 4, > > > running Linux 2.6.21, gcc 4.1.3, I get > > > > > > 3.0: 10 loops, best of 3: 728 msec per loop > > > 2.6: 10 loops, best of 3: 558 msec per loop > > > > > > So it's only 30% slower, not 260%. > > FWIW, I get > > >python -m timeit "import inttest; inttest.int_test2(5)" > 10 loops, best of 3: 367 msec per loop > > >\Apps\Python30\python -m timeit "import inttest; inttest.int_test2(5)" > 10 loops, best of 3: 810 msec per loop > > That's on Windows XP, distributed binaries of Python 2.5 and 3.0a1. > Processor speed: 1.7 GHz > Processor type: Intel(R) Pentium(R) M processor > > That's 120% slower (but against very different versions). > > I guess this proves nothing much, apart from the fact that the test is > wildly variable and as such probably not very valid :-)
The Pentium M and Pentium D are much more alike, architecturally, than either and the Pentium 4, although the per-clock performance of the Pentium M is much better than either the 4 or the D (although not *that* good compared to a D, I didn't think). In a test like this where the loop is reasonably tight (even given the trek through the python interpreter), processor architecture and differing compiler optimizations will likely have a pretty significant effect on the overall performance. Without looking into it at a much lower level, it's hard to tell, but the difference between a 1MB and 2MB L2 cache might make all the difference in 3.0 performance. -- Nick _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
