Claasen's logarithmic law of usefulness
[{{cite web, first=Brian, last = Dipert, year =1999, url=http://www.edn.com/electronics-blogs/other/4361480/It-s-elementary, title =It's elementary, publisher= EDN Magazine, accessdate = 2009-01-06
] is named after technologist Theo A. C. M. Claasen, who introduced the idea in 1999 when he was CTO of Philips Semiconductors:
: Usefulness =
log
Log most often refers to:
* Trunk (botany), the stem and main wooden axis of a tree, called logs when cut
** Logging, cutting down trees for logs
** Firewood, logs used for fuel
** Lumber or timber, converted from wood logs
* Logarithm, in mathe ...
(Technology)
The law can also be expressed as:
: Technology =
exp Exp may stand for:
* Exponential function, in mathematics
* Expiry date of organic compounds like food or medicines
* Experience points, in role-playing games
* EXPTIME, a complexity class in computing
* Ford EXP, a car manufactured in the 1980s
* ...
(Usefulness)
Examples
System parameters (e.g. RAM, CPU speed, disk capacity) need to increase by a multiple to create a noticeable impact on performance. In the case of RAM, by the law, a 256MB unit is only
1/
8 more practically useful than a 128MB unit though the base unit has doubled. It would require a 16384MB (128 × 128MB) unit of RAM to truly double performance under the law.
A modern car (e.g. a Ford Mondeo) is not substantially more useful at getting the occupants from A to B than an older car (e.g. a
Ford Model T
The Ford Model T is an automobile that was produced by Ford Motor Company from October 1, 1908, to May 26, 1927. It is generally regarded as the first affordable automobile, which made car travel available to middle-class Americans. The relati ...
)
Relation to Moore's law
In order to achieve a linear improvement in usefulness over time it is necessary to have an exponential increase in technology over time.
Moore's law
Moore's law is the observation that the number of transistors in a dense integrated circuit (IC) doubles about every two years. Moore's law is an observation and projection of a historical trend. Rather than a law of physics, it is an empir ...
delivers an exponential increase in technology, and so when Claasen's law is combined with Moore's law it implies a linear improvement in usefulness over time.
Notes
See also
*
List of eponymous laws
This list of eponymous laws provides links to articles on laws, principles, adages, and other succinct observations or predictions named after a person. In some cases the person named has coined the law – such as Parkinson's law. In other ...
Adages
Computer architecture statements
Rules of thumb