[dspillett]

> I have a 16 core M4 Max and running at a fraction of the potential maximum speed just isn't very optimal on modern CPUs like that.

To further muddy the waters: if your process is not bottlenecked at the CPU a modern unit might be more optimal in terms of power draw (directly and through secondary effects for increased cooling needs) running at a fraction of its speed. Moving at a low clock but fast enough not to become the bottleneck compared to other factors, instead of bursting to full speed for a bit then waiting, can be optimal.

Of course there are a bunch of chip specific optimisations here if you like complexity. Some chips are better off running all cores slowly, and others that can completely power down idle cores better off running a few faster, to optimise power use while getting the same job done in the same amount of wall-clock time.