Also, even if power usage matters, the optimum point may be shifted towards higher power points on desktop because as long as you're waiting for results, the sc

Also, even if power usage matters, the optimum point may be shifted towards higher power points on desktop because as long as you're waiting for results, the screen is shining, the disks are spinning, etc., so sacrificing CPU performance for CPU power efficiency may actually worsen energy consumption per unit of work done.