Layer 1 · How the heat leaves
Air cooling
General compute and any AI deployment under about 30 kW a rack.
The shape of it
- Capital cost
- Lowest
- Maturity
- proven
- Density supported
- Up to ~30 kW per rack
- PUE
- 1.4-1.6 typical
Verified 2026-09-06.
The catch
It runs out. The TCO crossover where liquid wins sits near 30 kW a rack at $0.12/kWh, and the thermal inflection near 45-50 kW. Above that, air is not a cheaper choice — it is not a choice.
What it actually decides
Still correct for most racks in most buildings. Simply not for the ones running frontier accelerators.
What this is powering
A GB200 NVL72 rack draws 120–132 kW and a GB300 pushes 135–200 kW, against a 2026 average rack of about 27 kW. The silicon decision and the power decision are the same decision, made eighteen months apart.
Layer 2 — Silicon · GB200 NVL72 · The 150 W inference option
Weighed against
- Air cooling vs Direct-to-chip liquid cooling — Where the crossover actually sits: about 30 kW a rack on cost, 45-50 kW on thermals.
Others in how the heat leaves
- Rear-door heat exchangers — ~30-50 kW per rack
- Direct-to-chip liquid cooling — 50-200+ kW per rack
- Single-phase immersion — 100+ kW per rack equivalent
- Two-phase immersion — Highest available
- Free and evaporative cooling — Depends on the paired system