Amdahl's law


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Amdahl's law

[′am‚dälz ‚lȯ]
(computer science)
A law stating that the speed-up that can be achieved by distributing a computer program over p processors cannot exceed 1/{f + [1 -f)/ p ]}, where f is the fraction of the work of the program that must be done in serial mode.

Amdahl's Law

(parallel)
(Named after Gene Amdahl) If F is the fraction of a calculation that is sequential, and (1-F) is the fraction that can be parallelised, then the maximum speedup that can be achieved by using P processors is 1/(F+(1-F)/P).

[Gene Amdahl, "Validity of the Single Processor Approach to Achieving Large-Scale Computing Capabilities", AFIPS Conference Proceedings, (30), pp. 483-485, 1967].

Amdahl's law

"Overall system speed is governed by the slowest component," coined by Gene Amdahl, chief architect of IBM's first mainframe series and founder of Amdahl Corporation and other companies. Amdahl's law applied to networking. The slowest device in the network will determine the maximum speed of the network. See laws.
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By deriving Amdahl's Law directly from parallel communication and parallel information processing theory, we demonstrate the roles played by communication channels, communication topology, and processor speeds in recasting the interpretation of the terms of the Law.
CONTENTS: Table of contents Executive summary In a nutshell Key messages Limitations of Moore's Law Symmetric multi-processing is the way forward SMP requires a different approach to software From serial execution to parallel programming Multi-cores versus many-cores Multiple cores create their own limitations The benefits and barriers of SMP Benefits of using SMP processors Barriers to using SMP processors Devices will go multi-core Customers are demanding higher performance ARM is driving embedded SMP adoption Operating system support for SMP is on its way Recommendations Service providers Handset manufacturers OS vendors Application vendors Table of figures Figure 1 Simplified illustration of SMP architecture Figure 2 Amdahl's Law
18 /PRNewswire/ -- Massively Parallel Technologies (MPT), a provider of on-demand high-performance computing, announced the company has developed the first mathematical derivation of Amdahl's Law.