Interestingly I tried this as well and was disappointed with the results:

  yes $(printf %1024s | tr " " "y") | pv > /dev/null

About the same throughput as letting yes output a single character. I guess Unix pipes are slow.

> I guess Unix pipes are slow.

Or string concatenation, or pipeviewer.

yes doesn't do string concatenation, at least not in the loop that matters. It just prepares a buffer of bytes once and writes it to stdout repeatedly.

https://github.com/coreutils/coreutils/blob/master/src/yes.c

Compare https://codegolf.stackexchange.com/questions/199528/fastest-...