supercomputer users on the mathematical aspects of software and on the data structures and computations that are used in scientific simulations. However, there has always been interplay between advances in supercomputing (hardware and software) and advances in mainstream computing.
There has been enormous growth in the dissemination and use of computing in the United States and in the rest of the world since the 1940s. The growth in computing use overall has been significantly greater than the growth in the use of supercomputing. As computing power has increased, some former users of supercomputing have found that their needs are satisfied by computing systems closer to the mainstream.
Conclusion: Supercomputing has always been a specialized form at the cutting edge of computing. Its share of overall computing has decreased as computing has become ubiquitous.
Supercomputing has been of great importance throughout its history because it has been the enabler of important advances in crucial aspects of national defense, in scientific discovery, and in addressing problems of societal importance. At the present time, supercomputing is used to tackle challenging problems in stockpile stewardship, in defense intelligence, in climate prediction and earthquake modeling, in transportation, in manufacturing, in societal health and safety, and in virtually every area of basic science understanding. The role of supercomputing in all of these areas is becoming more important, and supercomputing is having an ever-greater influence on future progress. However, despite continuing increases in capability, supercomputer systems are still inadequate to meet the needs of these applications. Although it is hard to quantify in a precise manner the benefits of supercomputing, the committee believes that the returns on increased investments in supercomputing will greatly exceed the cost of these investments.
Conclusion: Supercomputing has played, and continues to play, an essential role in national security and in scientific discovery. The ability to address important scientific and engineering challenges depends on continued investments in supercomputing. Moreover, the increasing size and complexity of new applications will require the continued evolution of supercomputing for the foreseeable future.
Supercomputing benefits from many technologies and products developed for the broad computing market. Most of the TOP500 listed systems are clusters built of commodity processors. As commodity processors have increased in speed and decreased in price, clusters have benefited. There is no doubt that commodity-based supercomputing sys-