I'd be curious to see how one measures peak energy density in a modern CPU. As far as power density goes, the i9-13900K seems to be 335W / (257 mm^2 die area *

I'd be curious to see how one measures peak energy density in a modern CPU. As far as power density goes, the i9-13900K seems to be 335W / (257 mm^2 die area * ~1mm water thickness) ≈ 1.3e9 W/m^3. The power density of the sun in comparison is around 2.8e2 W/m^3, roughly what you'd find at the center of a large pile of compost (although the temperature at the sun's core may be just a wee bit higher).