You could try with `/dev/urandom` to see if it's any faster.
random blocks when it runs low on entropy, but that seems unlikely to me in these small tests.
(urandom and random generally use the same secure pseudorandom algorithm, but urandom gracefully gives out arguably less secure values when entropy is low. The actual implementation is complicated, is different between older linux/newer linux/*bsd/macos, and is the subject of
many misconceptions that I sometimes fall into too.
)