The surprising usefulness of sloppy arithmetic
Ask a computer to add 100 and 100, and its answer will be 200. But what if it sometimes answered 202, and sometimes 199, or any other number within about 1 percent of the correct answer?Arithmetic circuits that returned such imprecise answers would be much smaller than those in today’s computers. They would consume less power, and many more of them could fit on a single chip, greatly increasing the number of calculations it could perform at once. The question is how useful those imprecise calculations would be.If early results of a research project at MIT are any indication, the answer is, Surprisingly useful. About a year ago, Joseph Bates, an adjunct professor of computer science at Carnegie Mellon University, was giving a presentation at MIT and found himself talking to Deb Roy, a researcher at MIT’s Media Lab. Three years earlier, before the birth of his son, Roy had...