[vgatherps]

Outside cases where Python is used as a thin wrapper around some C library (simple networking code, numpy, etc) 10x is frankly quite conservative. Depending on the problem space and how aggressively you optimize, it's easily multiple orders of magnitude.

[DiogenesKynikos]

Those cases are about 95% of scientific programming.

This is the first line in most scientific code:

    import numpy

[intelVISA]

FFI into lean C isn't some perf panacea either, beyond the overhead you're also depriving yourself of interprocedural optimization and other Good Things from the native space.