Hi, my findings are ont reproduced on a Linux Box:
typically: $ time /pathto/texlive/2016/bin/x86_64-linux/texlua collatz.lua 1 1000000 837799 real 0m23.755s user 0m23.720s sys 0m0.000s and $ time /pathto/texlive/2017/bin/x86_64-linux/texlua collatz.lua 1 1000000 837799 real 0m21.094s user 0m21.080s sys 0m0.000s I don't have an independent Lua interpreter installed here. And although timing varies up to 10%, it seems to the contrary the TL2017 version is a bit faster here. (TL2016 fully updated, TL2107 pretest fully updated) I would be interested to here about other architectures. Perhaps there is a special problem with x86_64-darwinlegacy ? Should I move the thread to texlive ? Best Jean-François
