Diamond may be computer chip's new best friend

Data centres squander vast amounts of electricity, most of it as heat. The physical properties of diamond offer a potential solution, researchers say.

- Amos Zeeberg

With tech companies racing to build more data centres housing servers that run the latest AI models, the amount of electricity these facilities consume is skyrocketing. But most of that electricity doesn’t power computing at all. It is squandered in the crudest way: as heat, spilling out of every one of the hundreds of billions of transistors in a modern chip.

"The dirty secret in chips is that more than half of all energy is wasted as leakage current at the transistor level," said R. Martin Roscheisen, an electrical engineer and entrepreneur at Diamond Foundry, a company in South San Francisco that manufactures specialised diamonds for use in electronics.

This heat is a great waste of energy that significantly shortens a chip's life and makes it run less efficiently, generating still more wasteful heat. Consequently, one of the critical tasks in data centres is keeping the temperature of servers down so they can run smoothly.

Mr Roscheisen is one of many engineers developing ways to embed tiny pieces of synthetic diamond, of all things, into chips to keep them cool. Diamond, in addition to being the hardest known material, is also exceptionally good at moving heat from place to place.

"Most people do not realise that diamond has the best heat-conduction properties of any material," said Paul May, a physical chemist at the University of Bristol in England. He added that diamond conducts heat several times faster than copper, a material often used in heat sinks for chips.

The high thermal conductivity of diamond arises from the same property that makes it so hard: Each carbon atom is bonded strongly to four neighbours, with no weak link in any direction. Those strong bonds are efficient at carrying the vibrations that move heat through a crystal.