Koomey, Jonathan. “The Computing Trend that Will Change Everything.” Technology Review, April 9, 2012.
From the article: "The performance of computers has shown remarkable and steady growth, doubling every year and a half since the 1970s. What most folks don't know, however, is that the electrical efficiency of computing (the number of computations that can be completed per kilowatt-hour of electricity used) has also doubled every year and a half since the dawn of the computer age.
Laptops and mobile phones owe their existence to this trend, which has led to rapid reductions in the power consumed by battery-powered computing devices. The most important future effect is that the power needed to perform a task requiring a fixed number of computations will continue to fall by half every 1.5 years (or a factor of 100 every decade). As a result, even smaller and less power-intensive computing devices will proliferate, paving the way for new mobile computing and communications applications that vastly increase our ability to collect and use data in real time." Read more
See also
Koomey, Jonathan G., Stephen Berard, Marla Sanchez and Henry Wong. “Implications of Historical Trends in the Electrical Efficiency of Computing.” IEEE Annals of the History of Computing 33, (July-September 2011): 46-54.
