They may often be used with small embedded computers, but 1 Coral TPU handily beats even a top-end CPU for the stuff Frigate needs it to do -- and it does it at minuscule power draw. Sure, it's inference-focused, and that means it has limitations: it sucks for e.g. speech models, too. But it's pretty great at what it does and gets used in real applications too. My guess is you saw the USB-C model, but they do M2, big cards with multiple M2 slots, and miniPCIe (popular in industrial applications) too.