Almost every technological innovation of the past several years has been laser-focused on one thing: generative AI. Many of these supposedly revolutionary systems run on big, expensive servers in a data center somewhere, but at the same time, chipmakers are crowing about the power of the neural processing units (NPU) they have brought to consumer devices. Every few months, it’s the same thing: This new NPU is 30 or 40 percent faster than the last one. That’s supposed to let you do something important, but no one really gets around to explaining what that is.