> Using 2000 cal per day/10 hours of thinking gives a consumption of ~200W

So, about a tenth or less of a single server packed to the top with GPUs.

That is true but there’s 3.7 billion years of evolutionary “design” to make self replicating, self fueling animals to use that brain. There’s no AI within foreseeable future capable of that. One might look at brains as a side effect of evolution of the self replicating, self fueling bits.

Are the wattage ratings of GPUs how many they need continuously or over hours?

Watts are a unit of power which is energy per time. specifically, 1 Watt is 1 joule per second