Your phone draws roughly one watt to play a video. Hold onto that number. It is the anchor for everything below. That single watt is the product of decades of ruthless optimisation. The display backlight and the fixed-function video decode block do almost all the work. Phone makers built dedicated silicon for H.265 and AV1 precisely because a general-purpose processor would burn ten times the energy for the same frames. Specialise, then power-gate everything you are not using. Now scale up. - Laptop under load: 45 to 90 W - Single Nvidia H100 accelerator: 700 W - Single Blackwell B200: up to 1,200 W - One GB200 NVL72 rack: around 120 kW That last figure is the fracture point. A conventional enterprise rack drew 7 to 12 kW. AI racks now pull ten times that in the same floor footprint, and heat flux at the die reaches 500 W per square centimetre. Air cooling collapses somewhere near 30 to 40 kW per rack. Removing 120 kW by forced air would demand roughly 85,000 cubic feet per minute ...