Whatever your alert threshold is, that still defines a fixed amount of work per machine and thus how many machines you need to satisfy a given workload. If you

Whatever your alert threshold is, that still defines a fixed amount of work per machine and thus how many machines you need to satisfy a given workload. If you need 100 machines to stay below your alert threshold, and you make a 1% improvement in efficiency, you now need 99 machines to stay below that same threshold. Whatever it is. For just about any load distribution that's not already problematic (e.g. if all of the load gets concentrated on one machine you're screwed no matter what). I work all day every day on dozens of clusters much bigger than that, and so do a lot of other people. For us, spending half a year to get a 1% improvement is an opportunity big enough to get excited about.