Reversible computing is ‘the only way’ to survive Intel's heat

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A researcher at the University of Florida has come up with a new set of chip designs called "reversible computers" that may steer chip makers away from creating incredibly hot processors and toward "green computing."

Michael Frank, an assistant professor at UF, created a way to re-engineer current chip designs, letting them recycle energy typically cast off as excess heat. The idea builds on decades of work and could well be the answer to extending Moore's Law for many years to come. By reusing energy with the help of tiny oscillators added to a chip's circuity, Frank hopes to make it possible for companies such as Intel and IBM to keep coming up with more powerful products.

"The long term goal of the program is to build computing devices that go through their cycle of operations just coasting from one cycle to the next," Frank said in an interview. "In the long run, reversible computing is the only thing we can do to keep pushing performance limits."

Frank's passion for green computing could not come at a better time. Intel often boasts of its designs that size-for-size will one day produce as much heat as a nuclear reactor. Register readers have tried in the past to deal with this problem via the discovery of the Gelsinger co-efficient. Whether or not Frank's research lives up to our own remains to be seen.

Current designs have chips fill with a charge and then dump that energy out in the form of heat every clock cycle. Frank hopes to recapture some of that energy by putting oscillators or mechanical springs on the chip's circuitry that can bounce energy back and forth between parts of the logic.

Frank believes that more efficient manufacturing processes and ever-shrinking transistors will open enough room on the silicon to add these oscillators.

"I don't anticipate the oscillators themselves taking up that much space," he said. "It's an area comparable to the logic that they power."

Other researchers are working on techniques such as quantum computing to help advance chip performance. But Frank is convinced that regardless of what designs engineers come up with, they will need the reversible computing technology to keep pushing GHz higher. The technology is of particular importance as we look twenty or thirty years out, he said.

"Ultimately, we are going to be limited by the logic gates themselves," he said. "In the long run, this is the only thing we can do."

Frank is asking large chip makers to consider the technology and start research on reversible computers now. During our interview, he happened to be joined by IBM Fellow Charles Bennett - a very IBM name.

Bennett, described by IBM as an expert in the physics of information, has done some pioneering work in the field of teleportation.

Even though we were on the phone, Bennett's voice was so clear that it seemed as if he had paid a visit to The Register offices. Figment of our imagination? You make the call.

What does he make of reversible computing?

"We got discouraged by it a few years ago, but I think it's time to look at it again," he said.

Reversible computing's efficient use of heat could make it possible to come up with 3-D chip designs, Bennett said. This would push all of the circuitry closer together and ultimately increase performance.

Frank is currently coming up with ways to outfit chip designs with the oscillators. More information on his work can be found here.