Thermal Density Console

Total package wattage is the number everyone quotes, but it's the wrong one for thermal design. What overheats a chip is concentration — heat per unit area, where it's densest. A package can have a comfortable average and still cook, because the compute die packs far more power into its area than the memory and I/O around it, and the cooling has to win that local battle at the hotspot, not the average fight across the whole package.

That's why the peak-to-average ratio matters so much. When the hottest die runs at several times the package average, you have a concentration problem that adding overall cooling capacity won't solve — you must cool that specific die harder. This console computes each die's flux, highlights the hotspot, and reports the ratio precisely so the concentration is visible rather than hidden inside a total.

Concentration is also a design lever, and it's one of the under-appreciated thermal arguments for chiplets. Splitting a design into chiplets spreads the same power across more silicon and a larger package, dropping the peak flux — the heat is simply easier to remove when it's less concentrated. Three-dimensional stacking is the opposite extreme: it piles power into the same footprint at multiple tiers, multiplying volumetric density and trapping it, which is exactly why stacks use low-power cache or memory on top rather than two hot compute dies.

Use this to find which die is the thermal villain and how concentrated the package is, then take the hotspot flux to the Power Density console to check it against cooling ceilings, and the 3D IC console for the stacked case.