You know the feeling when you open one too many new tabs and your laptop starts overheating? Data centres—rooms full of supercomputers that power every data transmission on the internet—have this same problem on a massive scale. And in order to cool the computers down, data centres consume the same amount of water as 1000 US households a day.
There are innovative solutions for putting this waste heat to good use, from heating swimming pools to warming our buildings. Computer scientists have also developed new lines of code that have the potential to improve the efficiency of data centres by five percent.
And now, a research team from computer hardware manufacturing company Lightmatter have discovered a new way to solve data centres’ waste heat problem. Their solution uses Photonic Integrated Circuits (PICs) instead of conventional digital circuits, essentially replacing electrons with photons: particles of light. Start-up Q.ANT is another company pioneering this field, with the first commercially available photonic processor on the market.
Photonic integrated circuits produce less waste heat—and require less cooling
The improved efficiency of PICs is twofold: because the circuits produce less waste heat, they also require less cooling than conventional digital circuits. This also means that data centres run on PICs would use less water.
While previous research has tested simple operations with PICs, the Lightmatter team focused on testing whether the design could handle AI model operations. The results showed that, when classifying images, the system achieved 90 percent of the accuracy of a standard processor. However, its accuracy dropped to just 30 percent when answering questions posed in natural language.
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Experts believe “this is ‘high-tech’ of the latest kind”
The Lightmatter team published their findings in Nature, after which the Science Media Centre provided independent comment on the study from two experts in the field.
Dr Damien Dudek, Managing Director of the VDE (Information Technology Society), believes the PIC “is ‘high-tech’ of the latest kind”. As well as “breaking new ground in terms of great energy efficiency”, it also “utilises the very latest production methods in the design of integrated semiconductor circuits”.
However, Dudek points out the scalability issues of the design: “the silicon-based components have reached their physical limits. This technology can only become established if it’s possible to scale.” He also urgently appeals for greater coordination of research funding between industry and research institutions.
Professor Mario Chemnitz, Junior Professor of Intelligent Photonic Systems and Head of the Smart Photonics Research Group, believes the design “marks a significant technological step for the field of photonic computing.” While “manufacturing processes and ultra-fast write and read electronics must become better and more energy-efficient”, he foresees that “photonic technologies could replace conventional processors in certain applications within five to ten years”.
Even with this development, we must continue to reduce our digital emissions, especially as AI technology makes every online interaction increasingly carbon-heavy. Improving efficiency of data centres is an effective solution—but only if we don’t lose sight of the many ways to reduce our digital carbon footprints.
