[galangalalgol]

This is a good point. Fine grained parallelism works well with c extensions, but coarse grained does not. Which is why data science and MATLAB like tasks are so often done in python without worrying too much about the python penalty. But if you have a lot of small dense matrix operations, even VBA in excel will be faster by more than 10x because you keep popping back into python.

[quietbritishjim]

I agree with the idea, but you have fine grained and course grained switched.