Cooling AI Computers: Following Heat and Water
Why would a computer need pipes?
How it works
Nearly all the electricity used by a chip becomes heat. Cooling carries heat away so computers work safely.
A cold plate (a metal part collecting chip heat) touches the chip. Liquid flows through small paths inside, collecting heat. A pump pushes liquid through pipes. A heat exchanger (equipment passing heat between fluids) keeps those fluids separate.
Cooler liquid returns to the chip. The loop collects more heat while computers work. Outside equipment releases heat outdoors or sends it for useful heating.
Water use depends on that outside equipment. Cooling towers remove heat by evaporating water (turning it into vapor). Closed loops reuse liquid. A separate cooling tower may still need fresh water.
Picture the scale
NVIDIA rates one DGX H100 computer system at up to 10.2 kilowatts, or 10,200 watts. Nearly all that electrical energy eventually becomes heat. Like the warm air leaving a laptop, the heat needs a path out—on a much larger scale.
Why should I care?
Your laptop's fan has a smaller version of the same job. Cooling the computers behind game updates can also use your town's electricity and water.
Words to know
- Cold plate
- A part that transfers chip heat to liquid; like a warm spoon giving heat to water.
- Pump
- A machine that moves liquid; like a pump circulating water in a fountain.
Check yourself
1. Liquid warms as it passes a chip. What did it collect?
- Extra fuel
- Heat
- Stored electrical charge
Show answer and why
B. Heat. Heat moves from the chip into the liquid.
2. What completes the cooling loop?
- A one-way drain after every pass
- A larger electrical bill
- A return path for cooler liquid
Show answer and why
C. A return path for cooler liquid. Returning liquid can collect heat again.
3. Why can a cooling tower use water?
- Some water evaporates while carrying heat away
- Water becomes electrical current
- Pipes must empty after every trip
Show answer and why
A. Some water evaporates while carrying heat away. Evaporation helps release heat into the surroundings.