Playing with now()'s clock skew effect at high call rates.

now_skew.erl

-module(now_skew).
-compile(export_all).

go() ->
    A = os:timestamp(),
    NA = now(),
    Master = self(),
    spawn(fun()->loop(1000000), Master!done end),
    %spawn(fun()->loop(500000), Master!done end),
    receive done->ok end,
    %receive done->ok end,
    B = os:timestamp(),
    NB = now(),
    DeltaNow = timer:now_diff(NB,NA),
    DeltaOS = timer:now_diff(B,A),
    [{now,DeltaNow}, {os,DeltaOS}, {diff,DeltaNow-DeltaOS}
    ,{skew,DeltaNow/DeltaOS}].

loop(0) -> done;
loop(N) -> now(), loop(N-1).