[chc]

I doubt they'll ever get even as fast as CPython for CPython API usage. What allows PyPy to run Python code fast is the same thing that makes the CPython API slow: The two implementations look nothing alike on the inside. The API is too leaky an abstraction to implement efficiently on anything but CPython.

[fijal]

While I agree with you, pypy already runs cffi fast and we are thinking how to run cython fast. That would cover a large subset of using C API I think.