Boffins at Vaire Computing have emerged from their smoke filled labs having built a test chip called Ice River that reuses part of the electricity it consumes, instead of instantly turning it all into heat.
Vaire's Top boffin Michael Frank said: “You use energy once and then throw it away. Ice River bucks that trend by cutting energy use by about 30 per cent during recent lab tests."
The trick lies in revisiting two assumptions baked into chip design for decades. Modern processors lose energy every time they erase data. Ice River uses reversible logic, which means computations can be run backwards to recover the original 1s and 0s rather than simply wiping them and generating heat.
Instead of hammering voltage levels up and down at speed, Ice River uses a gentler approach called adiabatic computing. Voltages rise and fall slowly, like a pendulum swinging, allowing energy to slosh back and forth inside the system rather than blowing off as waste heat. Crucially, the chip carries its power supply to make this feedback loop work.
Northeastern University engineer Aatmesh Shrivastava said: “This is quite exciting. We all want a computing system where we can recover energy."
Researchers have toyed with the theory since the 1960s, but Frank says Ice River is the first working silicon to combine reversible logic with on-chip adiabatic power. Earlier, he had worked on reversible systems at MIT in the 1990s, but this is the first time the two methods have been married together on real hardware.
The company’s cofounder Hannah Earley said seeing the chip work after years of sketches and simulations was “thrilling.”
Others in the field think the breakthrough had legs. Zettaflops boss Erik DeBenedictis said: “Much closer to a reversible chip that would be useful in the real world than anybody has come before."
The prototype is slow, and scaling it up will cost an arm and a legy. Because the design runs cooler, chips could be packed closer together to compensate, but that drives manufacturing expenses higher. Shrivastava cautioned that “this type of technology will take a long time to become more mainstream.”
