A New Kind of Microchip

Source:Technology Review
A probability-based processor may speed up flash memory, and eventually much more.

A computer chip that performs calculations using probabilities, instead of binary logic, could accelerate everything from online banking systems to the flash memory in smart phones and other gadgets.

Probability chip: This computer chip uses signals representing probabilities, not digital bits. Credit: Lyric Semiconductor

Rewriting some fundamental features of computer chips, Lyric Semiconductor has unveiled its first "probability processor," a silicon chip that computes with electrical signals that represent chances, not digital 1s and 0s.
"We've essentially started from scratch," says Ben Vigoda, CEO and founder of the Boston-based startup. Vigoda's PhD thesis underpins the company's technology. Starting from scratch makes it possible to implement statistical calculations in a simpler, more power efficient way, he says.

And because that kind of math is at the core of many products, there are many potential applications. "To take one example, Amazon's recommendations to you are based on probability," says Vigoda. "Any time you buy [from] them, the fraud check on your credit card is also probability [based], and when they e-mail your confirmation, it passes through a spam filter that also uses probability."

All those examples involve comparing different data to find the most likely fit. Implementing the math needed to do this is simpler with a chip that works with probabilities, says Vigoda, allowing smaller chips to do the same job at a faster rate. A processor that dramatically speeds up such probability-based calculations could find all kinds of uses. But Lyric will face challenges in proving the reliability and scalability of its product, and in showing that it can be easily programmed.

The electrical signals inside Lyric's chips represent probabilities, instead of 1s and 0s. While the transistors of conventional chips are arranged into components called digital NAND gates, which can be used to implement all possible digital logic functions, those in a probability processor make building blocks known as Bayesian NAND gates. Bayesian probability is a field of mathematics named after the eighteenth century English statistician Thomas Bayes, who developed the early ideas on which it is based.