Закон Белла о классах компьютеров

Bell's law of computer classes formulated by Gordon Bell in 1972 describes how types of computing systems (referred to as computer classes) form, evolve and may eventually die out. New classes of computers create new applications resulting in new markets and new industries.

Bell considers the law to be partially a corollary to Moore's law which states "the number of transistors per chip double every 18 months". Unlike Moore's law, a new computer class is usually based on lower cost components that have fewer transistors or less bits on a magnetic surface, etc. A new class forms about every decade. It also takes up to a decade to understand how the class formed, evolved, and is likely to continue. Once formed, a lower priced class may evolve in performance to take over and disrupt an existing class. This evolution has caused clusters of scalable personal computers with 1 to thousands of computers to span a price and performance range of use from a PC, through mainframes, to become the largest supercomputers of the day. Scalable clusters became a universal class beginning in the mid 1990s; by 2010, clusters of at least one million independent computers will constitute the world's largest cluster. Definition: Roughly every decade a new, lower priced computer class forms based on a new programming platform, network, and interface resulting in new usage and the establishment of a new industry. Established market class computers aka platforms are introduced and continue to evolve at roughly a constant price (subject to learning curve cost reduction) with increasing functionality (or performance) based on Moore's law that gives more transistors per chip, more bits per unit area, or increased functionality per system. Roughly every decade, technology advances in semiconductors, storage, networks, and interfaces enable the emergence of a new, lower cost computer class (aka "platform") to serve a new need that is enabled by smaller devices (e. g. more transistors per chip, less expensive storage, displays, i/o, network, and unique interface to people or some other information processing sink or source). Each new lower priced class is then established and maintained as a quasi independent industry and market. Such a class is likely to evolve to substitute for an existing class or classes as described above with computer clusters.

Bell's law of computer classes and class formation was first mentioned in 1970 with the introduction of the Digital Equipment PDP 11 mini to differentiate it from mainframes and the potentially emerging micros. The law was described in 1972 by Gordon Bell. The emergence and observation of a new, lower priced microcomputer class based on the microprocessor stimulated the creation of the law that Bell described in articles and Bell's books.

See also the several laws (e. g. Moore's law, Metcalfe's law) that describe the computer industry.