$#a = 1e6;;

say grep /$$/, `tasklist`;;
perl.exe                      6740 Console                    1     17,120 K

$n=1e6-1; $t=time; ++$a[ $_ ] for 0..$n; print time()-$t;;
0.242353916168213

say grep /$$/, `tasklist`;;
perl.exe                      6740 Console                    1     41,312 K