perl randomshuffle.pl 100 5
          Rate  hkey  samp  shuf   mpu
hkey   15844/s    --  -46%  -93%  -99%
samp   29546/s   86%    --  -86%  -98%
shuf  212991/s 1244%  621%    --  -86%
mpu  1519656/s 9491% 5043%  613%    --