Maybe less is better suited for your needs?
ls /usr/bin | less
For me, it works instantaneously on a 5 years old laptop with classic HDD, but head is equally fast.
You can terminate
less prematurely with q.
I guess your assumption about the source of the 1s delay is wrong, but maybe depends on your Unix-flavour or your shell, less or head command.
On Linux, with GNU-ls,
ls -R /usr | less
starts outputting immediately for me, while the whole output is running und running - so it is definitively not finished, before less starts. You might check, if you have a constant delay of 1s or maybe more, depending on the output or not.
I guess your 1s delay has a different reason, maybe the HDD is going to sleep and needs a wakeup?
Do you have such a delay for very few files too?