[monocasa]

Poorly designed or managed chips can reach the point that hot spots in the silicon literally melt, which happens at ~1400C. Thermodynamics sitting on an insulator (relative to the metal portions of the chip at least) on very small scales is very weird and can reach wild spot temps.

That's why chip thermals is its own whole subfield of physical design.

[pfdietz]

Sure, but the center of a PWR fuel rod reaches high temperature in normal operation. Uranium dioxide is not a great conductor of heat.

Chips have the advantage that the workings are right at the surface, mere microns from it. So the heat can easily get out. The power density in that thin surface layer can be very high. Perhaps similarly, the power density of a PV cell can be very high, if one just looks at the active layer where light is being absorbed. In CdTe this layer is < 1 micron thick. The energy delivered over the life of the cell per atom in this layer can approach that of nuclear reactions.

[pfdietz]

I will add that if we're talking about abnormal operation, say in a reactor meltdown, uranium dioxide can reach its melting point, 2865 C.

Anyway, it's a promising comparison, since the core of a PWR can reach volumetric power density of ~100 MW/m^3 (and probably higher in naval reactors). Servers can potentially be made very compact.