Wirth's law

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Wirth's law is a computing adage made popular by Niklaus Wirth in 1995.[1][2] It states that

or, colloquially, "software gets slower faster than hardware gets faster".

Computer hardware has become faster over time, and some of that development is quantified by Moore's law; Wirth's law points out that this does not imply that work is actually getting done faster.

Wirth attributed the saying to Martin Reiser, who, in the preface to his book on the Oberon System, wrote: "The hope is that the progress in hardware will cure all software ills. However, a critical observer may observe that software manages to outgrow hardware in size and sluggishness."[3] Other observers had noted this for some time before, indeed the trend was becoming obvious as early as 1987.[4]

The law was restated in 2009 and attributed to Larry Page, founder of Google. It has been referred to as Page's law.[5] The first use of that name is attributed to Sergey Brin at the Google I/O Conference 2009.[6]

Gates' law[edit]

Gates' law is a variant on Wirth's law, borrowing its name from Bill Gates,[7] the founder of Microsoft. It is a humorous and ironic observation that the speed of commercial software generally slows by 50% every 18 months, thereby negating all the benefits of Moore's law. This could occur for a variety of reasons: "featuritis", "code cruft", developer laziness, or a management turnover whose design philosophy does not coincide with the previous manager.[8]

May's law[edit]

May's law, named after David May, is a variant where:

See also[edit]


  1. ^ Niklaus Wirth (February 1995). "A Plea for Lean Software". Computer 28 (2): pp. 64–68. doi:10.1109/2.348001. Retrieved 2007-01-13. 
  2. ^ Philip E. Ross. "5 Commandments". IEEE Spectrum. 
  3. ^ Reiser, Martin (1991). The Oberon System User Guide and Programmer's Manual. ACM Press. ISBN 0-201-54422-9. 
  4. ^ Geoffrey Welsh (1987). "Yes, There IS a Difference Between Micros and 'Big' Computers". TPUG News 2 (1). 
  5. ^ "Can "Page's Law" Be Broken?". Slashdot. 
  6. ^ searchengineland (2009-05-27). "Sergey Brin On Breaking "Page's Law" Of Software Sluggishness". YouTube. Retrieved 2009-05-27. 
  7. ^ a b Gates' law, from the Jargon Lexicon, in the Jargon File (version 4.4.7).
  8. ^ Orion, Egan (March 21, 2003). "WinTel trips on Linux?", The Inquirer.
  9. ^ Eadline, Douglas. "May’s Law and Parallel Software". Linux Magazine. Retrieved 9 May 2011. 

Further reading[edit]

  • The School of Niklaus Wirth: The Art of Simplicity by László Böszörményi, Jürg Gutknecht, and Gustav Pomberger (editors), Morgan Kaufmann Publishers, 2000, ISBN 1-55860-723-4.