Definition
We all know that the silicon based chips are reaching a physical limit in processing speed, as they are constrained by the speed of electricity, light and certain thermodynamic laws. A viable solution to overcome this limitation is to connect multiple processors working in coordination with each other to solve grand challenge problems. Hence, high performance computing requires the use of Massively Parallel Processing (MPP) systems containing thousands of power full CPUs.

Processing of multiple tasks simultaneously on multiple processors is called Parallel Processing. The parallel program consists of multiple active processes simultaneously solving a given problem. A given task is divided into multiple sub tasks using divide-and-conquer technique and each one of them are processed on different CPUs. Programming on multiprocessor system using divide-and-conquer technique is called Parallel Processing.
The development of parallel processing is being influenced by many factors. The prominent among them include the following:

1.Computational requirements are ever increasing, both in the area of scientific and business computing. The technical computing problems, which require high-speed computational power, are related to life sciences, aerospace, geographical information systems, mechanical design and analysis, etc.
2.Sequential architectures reaching physical limitation, as they are constrained by the speed of light and thermodynamics laws. Speed with which sequential CPUs can operate is reaching saturation point ( no more vertical growth ), and hence an alternative way to get high computational speed is to connect multiple CPUs ( opportunity for horizontal growth ).

3.Hardware improvements in pipelining, super scalar, etc, are non scalable and requires sophisticated compiler technology. Developing such compiler technology is difficult task.

4.Vector processing works well for certain kind of problems. It is suitable for only scientific problems ( involving lots of matrix operations). It is not useful to other areas such as database.

5.The technology of parallel processing is mature and can be exploited commercially, there is already significant research and development work on development tools and environment is achieved.

6.Significant development in networking technology is paving a way for heterogeneous computing.
India launched a major initiative in parallel computing in 1988. There are five or six independent projects to construct parallel processing systems. This was motivated by the need for advanced computing, a vision of developing its own technology, and difficulties (political and economic) obtaining commercial products.

The creation of the Center for Development of Advanced Computing (C-DAC) and concurrently other efforts at National Aerospace Laboratory (NAL), Bangalore, Advanced Numerical Research & Analysis Group (ANURAG), Hyderabad, Bhabha Atomic Research Center (BARC), Bombay, Center for Development of Telematics (C-DOT), Bangalore, marked the beginning of high performance computing in India.