Bad Chips Can Make Smartphones Cheaper, More Energy Efficient
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Researchers at the Telecommunications Circuits Lab at EPFL have found that defective computer chips could be used in smartphones and other electronics while still keeping the same level of performance and majorly boosting energy efficiency.
The researchers, led by Andreas Burg, say smartphones and laptops are resilient to a certain level of distortions of the signal they process because they have to be -- wireless networks are full of noise and often encounter interference. When a smartphone visits a webpage, it typically only processes and stores 90 percent of the data on the first attempt, but through sophisticated error correction mechanisms by the application its running or by the device running an automatic repeat request, its able to fill in the gaps in data.
This ability to work within the limits of wireless networks led to the researcher's theory that smartphones should be similarly resilient to a certain amount of not-fully-reliable silicon chips in their circuits. Says Burg, "Manufacturers don’t produce chips that can run at very low voltage and be energy efficient, because the production yield would be low -- most of the chips, after production, are unusable. Thanks to our technique, we can use the partially functional chips that would otherwise be thrown away, and maintain a high yield."
According to EPFL:
To test the theory, Burg's team and his colleagues at ETHZ designed a simulation system that evaluates the impact of hardware “failures” in the memory of a smartphone. The results showed that the system was able to tolerate a large number of such defects in the circuit: neither the throughput nor the performances of the smartphone were significantly affected. Even better, the system could run longer on a single battery charge.
Basically, exploiting the phone's ability to tolerate defects when it's operating at a lower voltage can lead to phones that run on a much lower power supply. It will make some tasks slower, like sending emails, but the researchers insist the performance will be overall the same. This could lead to the production of cheap smartphones that run purely on these discarded chips. They would be slower, but just as useful.
This research echoes the work being done at Rice University on "inexact" computer chips. That group has designed a computer chip that is faster, more energy efficient and smaller by making occasional mistakes. Researchers at EPFL, Rice University and others have joined together to work on further developing "bad" chips for efficient electronics.