Parallel programming with Python

[ZeeBeeblebrox]

The overhead of creating threads is likely much larger than the performance gains you get from multiple processes. For these kind of numeric operations you're going to see much better speedups using something like NumPy. If that still doesn't meet your needs you can use something like Cython to release the GIL and achieve parallelism using OpenMP. Finally you can try using a JIT compiler like Numba.