The physical limits of computing is:

> At 20 °C (room temperature, or 293.15 K), the Landauer limit represents an energy of approximately 0.0175 eV, or 2.805 zJ. Theoretically, room-temperature computer memory operating at the Landauer limit could be changed at a rate of one billion bits per second (1 Gbit/s) with energy being converted to heat in the memory media at the rate of only 2.805 trillionths of a watt (that is, at a rate of only 2.805 pJ/s).

Which means trillions of times less power than a lightbulb for a gigabyte internet is the theoretical limit.

Maybe zettabit/s computing power on a lightbulb of energy.