Serial    threads  MCE::Hobo  MCE::Loop  MCE::Child

Linux      74.488s    25.345s    20.217s    17.932s     17.291s
macOS      84.010s    24.844s    24.505s    23.786s     23.069s
Windows   102.055s    29.702s    37.913s    28.376s     27.839s
Cygwin    162.474s    -------    50.092s    45.318s     43.949s
FreeBSD   107.569s    -------    31.138s    30.530s     30.050s

   threads is slow on Cygwin, so stopped due to taking too long.
   My FreeBSD has an older Thread::Queue missing the ->end method.