PyPy has higher memory overhead for very small units of work but usually once you do more than a couple of seconds of work it usually uses significantly less me

PyPy has higher memory overhead for very small units of work but usually once you do more than a couple of seconds of work it usually uses significantly less memory than CPython. As far as I'm concern who cares if a Hello World program uses more memory or some small trivial few lines of code. I'm more interested in real world code which my experience has been that PyPy uses significantly less memory than CPython. If you know of a case where this is not true report it as I'm sure the PyPy devs will consider it a bug. PyPy also has a slower startup time/overhead so very small amounts of work may end up slower than CPython but in general larger chunks of work will be faster if not its a bug and should be reported. There is currently some work going on to improve the C extension issue. It's currently in its beginning stages and its goals are to provide both a significant amount of compatibility with existing extensions and a significant reduction in the overhead to call out to C extensions over what is currently implemented in PyPy. On the performance side the new approach was said to remove about 40% of the existing overhead. There are tons of corner cases that still need to be worked on for the new approach to become production worthy and there is no guarantee that there will be no show stoppers that come up or that the tail of corner cases that need to be dealt with becomes a nightmare and the approach is abandoned. If this works succeeds, it will be a game changer as suddenly the majority of libraries would then become compatible with PyPy.