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Massively parallel

 

(Massively Parallel Processing or Massively Parallel Processor) A multiprocessing architecture that uses up to thousands of processors. Some might contend that a computer system with 64 or more CPUs is a massively parallel processor. However, the number of CPUs is not as much the issue as the architecture. MPP systems use a different programming paradigm than the more common symmetric multiprocessing (SMP) systems used as servers.

In an MPP system, each CPU contains its own memory and copy of the operating system and application. Each subsystem communicates with the others via a high-speed interconnect. In order to use MPP effectively, an information processing problem must be breakable into pieces that can all be solved simultaneously. In scientific environments, certain simulations and mathematical problems can be split apart and each part processed at the same time. In the business world, a parallel data query (PDQ) divides a large database into pieces. For example, 26 CPUs could be used to perform a sequential search, each one searching one letter of the alphabet.

To take advantage of more CPUs in an MPP system means that the specific problem has to be broken down further into more parallel groups. However, adding CPUs in an SMP system increases performance in a more general manner. Applications that support parallel operations (multithreading) immediately take advantage of SMP, but performance gains are available to all applications, simply because there are more processors. For example, four CPUs can be running four different applications. See SMP.

MPP and SMP Architecture
In MPP operation, the problem is broken up into separate pieces, which are processed simultaneously. In SMP, CPUs are assigned to the next available task or thread that can run concurrently.

An Integrated Architecture
This early Reliant 1000 from Pyramid (later Fujitsu Siemens) was an MPP machine that was combined with SMP systems to provide both kinds of processing. The SMP systems attached to the Reliant's high-speed mesh interconnect, providing an unusual degree of flexibility and scalability. (Image courtesy of Pyramid Technology Corporation.)

ServerNet Interconnect
This is a conceptual diagram of the advanced ServerNet interconnect architecture from Tandem (later acquired by Compaq), which functioned as a high-speed switch between CPUs and I/O subsystems. It was used for both MPP applications and clusters of SMP systems. The purple and orange units are the processors and disks. The green pipes are the ServerNet mesh. (Image courtesy of Tandem Computers Incorporated.)

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Wikipedia: Massively parallel
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Massively parallel is a description which appears in computer science, life science, medical diagnostics, and other fields.

A massively parallel computer is a distributed memory computer system which consists of many individual nodes, each of which is essentially an independent computer in itself, and in turn consists of at least one processor, its own memory, and a link to the network that connects all the nodes together. Nodes communicate by passing messages, using standards such as MPI. Nearly all supercomputers as of 2005 are massively parallel, with the largest having several hundred thousand CPUs. The cumulative output of the many constituent CPUs can result in large total peak FLOPS (FLoating point Operations Per Second) numbers. The true amount of computation accomplished depends in the nature of the computational task and its implementation. Some problems are more intrinsically able to be separated into parallel computational tasks than others. When problems depend on sequential stages of computation, some processors must remain idle while waiting for the result of calculations from other processors, resulting in less efficient performance. The efficient implementation of computational tasks on parallel computers is an active area of research. See also Parallel computing.

Through advances in Moore's Law, single chip implementations of massively parallel architectures are becoming cost effective. Examples include chips from Ambric, ASOCS and picoChip.

In life science and medical diagnostics, massively parallel chemical reactions are used to reduce the time and cost of an analysis or synthesis procedure, often to provide ultra-high throughput. For example, in ultra-high-throughput DNA sequencing as introduced in August 2005 there may be 500,000 sequencing-by-synthesis operations occurring in parallel.[1]

See also

References

  1. ^ Gilbert Kalb, Robert Moxley (1992). Massively Parallel, Optical, and Neural Computing in the United States. Moxley. ISBN 9051990979. 

 
 

 

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