Bell's law of computer classes
Bell's law of computer classes formulated by Gordon Bell in 1972 describes how types of computing systems form, evolve and may eventually die out. New classes of computers create new applications resulting in new markets and new industries.
Description
Bell considers the law to be partially a corollary to Moore's law which states "the number of transistors per chip doubles 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.Established market class computers are introduced and continue to evolve at roughly a constant price with increasing functionality 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 to serve a new need that is enabled by smaller devices. 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.
Computer classes that conform to the law
- mainframes
- minicomputers
- personal computers and workstations evolving into a network enabled by Local Area Networking or Ethernet
- web browser client-server structures enabled by the Internet
- cloud computing, e.g., Amazon Web Services or Microsoft Azure
- hand held devices from media players and cell phones to tablets, e.g., Creative, iPods, BlackBerrys, iPhones, smartphones, Kindles, iPads
- wireless sensor networks that enable sensor and actuator interconnection, enabling the evolving Internet of things