There is no way that you can get a 40% reduction in total CPU power consumption, much less system power consumption, just by lowering the voltage of the memory

There is no way that you can get a 40% reduction in total CPU power consumption, much less system power consumption, just by lowering the voltage of the memory -- the entire contribution of the memory is a tiny fraction of the system's power budget. Reducing power consumption by an imperceptibly small fraction of a fraction of a percent is just an excuse.