Koomey's law describes a trend in the history of computing hardware: for about a half-century, the number of computations per joule of energy dissipated doubled about every 1.57 years. Professor Jonathan Koomey described the trend in a 2010 paper in which he wrote that "at a fixed computing load, the amount of battery you need will fall by a factor of two every year and a half."[1]
This trend had been remarkably stable since the 1950s (R2 of over 98%). But in 2011, Koomey re-examined this data[2] and found that after 2000, the doubling slowed to about once every 2.6 years. This is related to the slowing[3] of Moore's law, the ability to build smaller transistors; and the end around 2005 of Dennard scaling, the ability to build smaller transistors with constant power density.
"The difference between these two growth rates is substantial. A doubling every year and a half results in a 100-fold increase in efficiency every decade. A doubling every two and a half years yields just a 16-fold increase", Koomey wrote.[4]
- ^ Koomey, Jonathan; Berard, Stephen; Sanchez, Marla; Wong, Henry (March 29, 2010), "Implications of Historical Trends in the Electrical Efficiency of Computing", IEEE Annals of the History of Computing, 33 (3): 46–54, doi:10.1109/MAHC.2010.28, ISSN 1058-6180, S2CID 8305701.
- ^ Koomey, Jonathan G. (November 29, 2016). "Our latest on energy efficiency of computing over time, now out in Electronic Design".
- ^ Clark, Don (July 16, 2015). "Intel Rechisels the Tablet on Moore's Law". Wall Street Journal.
- ^ Naffziger, Sam; Koomey, Jonathan (November 29, 2016). "Energy Efficiency of Computing: What's Next?". Electronic Design.