Researchers have unveiled an “inexact” computer chip that challenges the industry’s 50-year pursuit of accuracy. The design improves power and resource efficiency by allowing for occasional errors. Prototypes unveiled this week at the are at least 15 times more efficient than today’s technology.


The concept is deceptively simple: slash power use by allowing processing components — like hardware for adding and multiplying numbers — to make a few mistakes. By cleverly managing the probability of errors and limiting which calculations produce errors, the designers have found they can simultaneously cut energy demands and dramatically boost performance.

One example of the inexact design approach is “pruning”, or trimming away some of the rarely used portions of digital circuits on a microchip. The researchers showed that pruning some sections of traditionally designed chips could boost performance in three ways: the pruned chips were twice as fast, used half as much energy and were half the size.


Particular types of applications can tolerate quite a bit of error. When using inexact adders to process images it was found that relative errors up to 0.54 percent were almost indiscernible and relative errors as high as 7.5 percent still produced discernible images. Possible initial applications for the pruning technology will be hearing aids, cameras and other electronic devices.

The research, which earned best-paper honors at the ACM International Conference on Computing Frontiers in Cagliari, Italy, was conducted by experts from Rice University in Houston, Singapore’s Nanyang Technological University (NTU), Switzerland’s Center for Electronics and Microtechnology (CSEM) and the University of California, Berkeley.