do so in the future. Some kinds of export controls—on commodity systems, especially—lack any clear rationale, given that such systems are built from widely available commercial components. It makes little sense to restrict sales of commodity systems built from components that are not export controlled. Because restrictions on the export of supercomputing technology may damage international collaboration, the benefit of using export controls to prevent potential adversaries or proliferators from accessing key supercomputing technology has to be carefully weighed against that damage.
Since supercomputer systems are multipurpose (nuclear simulations, climate modeling, and so on), their availability need not compromise the domestic leadership needed for national defense, so long as safeguards are in place to protect critical applications.
Recommendation 8. The U.S. government should ensure that researchers with the most demanding computational requirements have access to the most powerful supercomputing systems.
Access to the most powerful supercomputers is important for the advancement of science in many disciplines. A model in which top supercomputing capabilities are provided by different agencies with different missions is healthy. Each agency is the primary supporter of certain research or mission-driven communities; as such, each agency should have a long-term plan and budget for the acquisition of the supercomputing systems that are needed to support its users. The planning and funding process followed by each agency must ensure stability from the viewpoint of its users.
The users should be involved in the planning process and should be consulted in setting budget priorities for supercomputing. The mechanisms for allocating supercomputing resources must ensure that almost all of the computer time on capability systems is allocated to jobs for which that capability is essential. Budget priorities should be reflected in the high-end computing plan proposed in Recommendation 1. In Chapter 9, the committee estimates the cost of a healthy procurement process at about $800 million per year. Such a process would satisfy the capability supercomputing needs (but not the capacity needs) of the main agencies using supercomputing and would include the platforms primarily used for research. It would include both platforms used for mission-specific tasks and platforms used to support science.
The NSF supercomputing centers have traditionally provided open access to a broad range of academic users. However, some of these centers have increased the scope of their activities in order to support high-speed networking and grid computing and to expand their education mission. The increases in scope have not been accompanied by corresponding in-