priority.2 Leadership in supercomputing is an important component of overall leadership in science and engineering.
By its very nature, supercomputing has always been characterized by higher performance than mainstream computing. However, as the price of computing has dropped, the cost/performance gap between mainstream computers and top-priced supercomputers has increased. The computer market has grown most vigorously at the bottom end (cheap PCs and low-end servers). The share of that market devoted to supercomputing has diminished, and its importance in economic terms to hardware and software vendors has decreased. Even within supercomputing, the relative weight of the most challenging systems, those based on custom components, has decreased as an increasing number of supercomputer users are having their needs met by high-end commodity systems. Yet some essential needs can only be met by custom components. Consequently, market forces are less and less natural drivers of advances in supercomputing-specific technologies.
Supercomputer systems are highly complex. Supercomputing is, almost exclusively, parallel computing, in which parallelism is available at all hardware and software levels of the system and in all dimensions of the system. The coordination and exploitation of those aspects of parallelism is challenging; achieving balance among the aspects is even more challenging.
Ecosystem creation is both long term and expensive. The amalgam of expertise, technology, artifacts, and infrastructure that constitutes a supercomputing ecosystem is developed over a significant period of time. To get all the necessary components in place, a lot of effort is required. The nurturing of human talent, the invention of new ideas and approaches, and the use of those ideas and approaches in hardware and software artifacts all require significant investment. Given the lead time needed, and the fact that a given ecosystem has a bounded lifetime, investment in future ecosystems is needed to sustain leadership.
Given that leadership in supercomputing is essential to the government, that supercomputing is expensive, and that market forces alone will not drive progress in supercomputing-directed technologies, it is the role of the government to ensure that supercomputing appropriate to our needs is available both now and in the future. That entails both having the necessary activities in place in an ongoing fashion and providing the funding to support those activities.