I said I/O, but it could be memory access. All he does fits in registers and maybe cache. Also, 0.01ms was the normal RAM latency when I started using computers

I said I/O, but it could be memory access. All he does fits in registers and maybe cache. Also, 0.01ms was the normal RAM latency when I started using computers... Do you remember the last time you had to do a tight calculation loop, and not only that, but one that significantly impacted the total runtime? Personally I do, it was roughly 15 years ago writing a raytracer. I can imagine that happening in game/3D dev, DSP, emulators, ML, and maybe some other types of software, but even in those cases one already has dedicated libraries and hardware to extract the performance from where it can be extracted. I mean, Python is slow as an old dog, yet it gets most of the ML fun.