pickle faster than cPickle with numeric data?
The (binary representation of) the numeric data of an ndarray is pickled as one long string. It appears that cPickle is indeed much slower than pickle in unpickling large strings from protocol 0 files. Why? My guess is that pickle makes use of well-tuned string algorithms from the standard library and cPickle has fallen behind.
The observation above is from playing with Python 2.7. Python 3.3, which uses a C extension automatically, is faster than either module on Python 2.7, so apparently the issue has been fixed.