In one approach, e.g., in grid computing the processing power of many computers in distributed, diverse administrative domains, is opportunistically used whenever a computer is available. An example is BOINC, a volunteer-based, opportunistic grid system, whereby the grid provides power only on a best effort basis.
In another approach, many processors are used in close proximity to each other, e.g., in a computer cluster. In such a centralized system the speed and flexibility of the interconnect becomes very important, and modern supercomputers have used various approaches ranging from enhanced Infiniband systems to three-dimensional torus interconnects.
The term also applies to massively parallel processor arrays (MPPAs), a type of integrated circuit with an array of hundreds or thousands of central processing units (CPUs) and random-access memory (RAM) banks. These processors pass work to one another through a reconfigurable interconnect of channels. By harnessing many processors working in parallel, an MPPA chip can accomplish more demanding tasks than conventional chips. MPPAs are based on a software parallel programming model for developing high-performance embedded system applications.
- Grid computing: experiment management, tool integration, and scientific workflows by Radu Prodan, Thomas Fahringer 2007 ISBN 3-540-69261-4 pages 1–4
- Parallel and Distributed Computational Intelligence by Francisco Fernández de Vega 2010 ISBN 3-642-10674-9 pages 65–68
- Knight, Will: "IBM creates world's most powerful computer", NewScientist.com news service, June 2007