Interesting, tried myself on a test VM ~/test$ time for I in `seq -w 1 1000000`; do touch $I; done real 27m8.663s user 14m15.410s sys 12m24.411s OK

Interesting, tried myself on a test VM ~/test$ time for I in `seq -w 1 1000000`; do touch $I; done real 27m8.663s user 14m15.410s sys 12m24.411s OK ~/test$ time ls -1f | wc -l 1000002 real 0m0.604s user 0m0.180s sys 0m0.422s ~/test$ time ls -f | wc -l 1000002 real 0m0.574s ~/test$ time perl -E 'opendir(my $d,".");say while readdir $d' |wc -l 1000002 real 0m0.597s All seems reasonable. Directory size alone is 23M, somewhat larger than the typical 4096 bytes.