An alternative form of computer chip called a memcomputer could offer benefits over existing machines, and now a proof-of-principle digital memcomputer shows how these devices could be scaled up.

The first practical example of a new kind of computer can complete calculations in minutes that would take a standard version longer than the age of the universe. This so-called digital memcomputer, which combines data storage and processing into a single component, could be a solution to the slowing pace of progress in traditional computer chips.

Traditional computer chip designs are reaching their limit Yuichiro Chino/Moment RF/Getty Images |

Theoretically, ordinary computers can solve any computational problem by carrying out single logical operations in a processor, storing the result in memory, and moving on to the next operation until the calculation is complete. In practice, this shuttling of data back-and-forth between components means some calculations take an impractically long time.

Memcomputers offer an alternative approach, using a single type of component called computational memory that handles both processing and memory functions at once. Many of these can operate in parallel, rapidly working together to find a solution. The downside is that memcomputers aren’t general-purpose problem-solvers, but must be designed to handle specific calculations.

Until now, those designs have been analogue, with computational memory units storing data as electrical signals of varying voltage. While these circuits were able to solve problems, tiny variations in these voltages mean that scaling them up also scaled up noise and quickly rendered outputs meaningless.

Now, Massimiliano Di Ventra at the University of California, San Diego and his colleagues have now constructed a digital memcomputer, using binary numbers to store data, that they believe can be scaled-up to handle practical tasks.

The team’s version is designed to solve a combinatorial problem common in standard computer chip design. “These are really tough problems,” says Di Ventra.

A standard computer would need to methodically work through vast numbers of potential solutions sequentially until it stumbled across the correct one, but the memcomputer can find a solution in minutes. “It would take over the age of the universe if you actually did it with standard algorithms,” says Di Ventra. “There’s no way you can do it.”

“Since the 1960s, computational power has been largely driven by the ability to fit in more and more transistors,” says Neil Kemp at the University of Nottingham, UK, but chip designers are now reaching the limits of what is physically possible.

“Computing has become a little bit cleverer in terms of looking at new architectures and not being driven just by making transistors smaller and smaller,” he says, adding that if research continues apace, then all computers could one day have dedicated memcomputing chips to handle certain tasks.

“It’s under the radar a little bit at the moment, but we’ve solved a lot of very tough problems,” says Di Ventra. “We’re interested only in really tough problems, because for simple ones you can always use standard algorithms.”

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