More efficiently in the sense that, on a ROI basis, there's now more R on the I of 3D stacking, than there is in the I of increasing transistor density. Agreed

More efficiently in the sense that, on a ROI basis, there's now more R on the I of 3D stacking, than there is in the I of increasing transistor density. Agreed that Moore's law was about increasing density of transistors on a chip - but you can do that in various ways. The article was clear to state, "Moore’s Law, he emphasizes, is simply a prediction about how many transistors can fit in a given area of IC—whether it’s done, as it has been for decades, in a single layer or by stacking multiple layers."