Today’s announcement from Microsoft, based on technology invented by Microsoft Research, is poised to advance the way AI (and other) systems are built. The innovation uses simple LED chips to transmit data, instead of copper wires or fiber-optic (laser-based) communication.
https://aka.ms/AA101ymw
The commercialization of this invention will make our AI datacenters consume less energy, be more reliable, and open additional design options to make our systems much better. Microsoft decided to share this invention with the world and make it widely available, as lower energy consumption across the industry is good for all of us.
Sending data along copper cables using electric pulses is standard because copper is cheap. As you increase data transmission rates, the copper wires must get shorter. That limitation has forced us to place AI and other chips ever closer together, creating a rapid increase in a rack’s power density, and making the challenges of cooling the rack much harder. That trend is unsustainable.
The other alternative today is the use of lasers over fiber optic cables. Fiber optics can go long distances and transmit data at high bandwidth. The challenge with using them is that the laser-based transmitters are bulky, expensive, have relatively high failure rates, and consume much more power than copper.
A Microsoft Research team in our Cambridge Lab had an out-of-the-box idea to address this problem in 2020: Use commercial LED chips (like we have in our cell phones) to transmit thousands of parallel streams of data at low power over low-cost medical imaging fiber. This breakthrough will allow the computing industry to transmit data with less power—at high bandwidth—than either copper or fiber optics, up to distances of tens of meters, at potentially higher reliability. The team solved many problems along the way, getting the LEDs to cycle at high speeds while remaining power efficient, finding a way to transmit those many streams of light reliably, coupling the light into the imaging fiber (since LEDs spread light in all directions), and keeping dispersion of the light sufficiently low that it can work over the target distances reliably. They formed a deep partnership with product engineers in Microsoft’s Azure Core, Azure Hardware, and M365 divisions and external partners (MediaTek and others). Together with their partners, they built a proof-of-concept solution that is plug-compatible with today’s datacenter cables.
Microsoft Research teams are free to explore any ideas or fundamental research. When they produce a breakthrough, we have decades of experience getting new technology to world-wide scale. But it takes grit, and I’m proud of the perseverance of the team. Thanks to Ariel Gomez Diaz, Junyi Liu, Kai Shi, Kaoutar Benyahya, Marianna Pantouvaki, Shawn Yohanes Siew, Doug Kelly, Daniel Cletheroe ,Vassily Lyutsarev, Brian Robertson, Thomas Burridge, and Paolo Costa--and all of their collaborators--for their hard work.
