I'm revisiting a project that I haven't touched in over a year. It was written in Python 2.6, and executed on 32-bit Ubuntu 10.10. I experienced a 20% performance increase when I used Psyco, because I had a computationally-intensive routine which occupied most of my CPU cycles, and always received the same data type. (Multiprocessing also helped, and I was using that too.)
I have now migrated to a 64-bit Ubuntu 12.10.1, and Python 3.3. I would rather not revert to my older configuration. That being said, it would appear from my initial reading that 1) Psyco is considered obsolete and is no longer maintained, 2) Psyco is being superseded by PyPy, 3) PyPy doesn't support Python 3.x, or 64-bit optimizations. Do I understand all that correctly? I guess I can live with the 20% slower execution, but sometimes my code would run for three solid days... -- http://mail.python.org/mailman/listinfo/python-list
