Glenn Knickerbocker <NotR@bestweb.net> wrote in
news:lm72s7dmh3pv607i0ik52j0r1v1s2d4csp@4ax.com:

> Whatever it is, it hates a stem that's already sorted but loves one
> sorted in two halves:

Quicksort doesn't like already sorted input. If the implementation isn't
careful, it can degenerate to n-squared performance. Perhaps that's what's
happening with SysStemSort.