compared to all the other things your cpu is doing,
and all the time your cpu sits there doing nothing,
the "waste" in this case pales to total unimportance.
you've got a supercomputer; you might as well use it.
An idle core will definitely use less power than one constantly processing. That is what drains the battery in your laptop. I'd rather not spend my battery power if it can be done on the server instead.
