Do you have a specific reference? This Mead paper[1] suggests "...a factor of 10 million more efficient than the best digital technology that we can imagine"..

Do you have a specific reference? This Mead paper[1] suggests "...a factor of 10 million more efficient than the best digital technology that we can imagine"...which I interpreted as a gross approximation at the chip level assuming 10nm process, not considering any particular architecture, and doesn't include roughly 2-3 orders of magnitude reduced efficient at the system level. [1] http://authors.library.caltech.edu/53090/1/00058356.pdf http://authors.library.caltech.edu/53090/1/00058356.pdf