Layer 1 · head to head
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.
| Air cooling | Direct-to-chip liquid cooling | |
|---|---|---|
| Capital cost | Lowest | Higher than air; lower than immersion |
| Density supported | Up to ~30 kW per rack | 50-200+ kW per rack |
| PUE | 1.4-1.6 typical | 1.1-1.2 |
| Maturity | proven | proven |
Air cooling
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.
Decides: Still correct for most racks in most buildings. Simply not for the ones running frontier accelerators.
Direct-to-chip liquid cooling
The catch: Cold plates capture most of the heat; the rest still leaves as air, so you keep a hybrid air path. It is not a full replacement for the existing system.
Decides: The 2026 production method, full stop. It holds 47% of the AI datacentre liquid cooling market on the strength of standard rack compatibility and a straightforward retrofit path.