It is hard to tell from some of the release statements when they mean a particular thing is an improvement over CPython or over previous performance by PyPy, e.g.:
>Specialized list implementation. There is a branch that implements lists of integers/floats/strings as compactly as array.array. This should drastically improve performance/memory impact of some applications
Is this improvement over CPython or over previous implementation in PyPy? There are several such comments.
Currently, PyPy is faster than CPython at pretty much anything (except when C is involved, for example, but they are working on that, too). You can see their benchmarks and comparisons at http://speed.pypy.org/.
What I think they mean by those statements is that this will improve performance over the previous version of PyPy - therefore - improve over CPython as well.
I'd say this particular improvement is necessarily in pypy, because plain lists are always boxed in CPython, which doesn't perform any of that kind of type specific optimizations, being a plain old interpreter.
>Specialized list implementation. There is a branch that implements lists of integers/floats/strings as compactly as array.array. This should drastically improve performance/memory impact of some applications
Is this improvement over CPython or over previous implementation in PyPy? There are several such comments.