Making computer chips is not as easy as it sounds. Manufacturers throw out 20–50% of the chips they make because of defects. According to a USC professor, Melvin Breuer, many of these defects are so minor that the chips could still be used in video cards and audio applications without a problem. He feels that if the manufacturers could identify these chips, they could resell them and drive the cost of electronic devices down to an amount in the billions of dollars each year of savings.
The technique doesn’t have to be limited to chips that are consistent in their errors. Chips that make errors only once in a while can also be spared, according to Breuer. They just need to end up in devices where humans can tolerate a glitch in the output from time to time. For instance, a video card could mark one pixel in a million as red instead of blue and an end user probably wouldn’t even notice the difference. The same goes for a soundcard in a voicemail application that blurs one word in every thousand. At present, chips failing these tests are usually tossed.