One can also argue that they are important for national security. However, it has been difficult to find constituencies willing to fight for these applications in the export control debate. In conducting our research, we were surprised at how difficult it was to find individuals within the Departments of Defense or Energy who were willing and able to argue for a continuation of export controls at the workstation or modest multiprocessor levels to protect applications within their spheres of activity. Without such constituencies, the first basic premise is weakened. A number of issues remain unresolved.
Parallel architectures based on commercial microprocessors dominate today's multiprocessor markets.
These systems are increasingly easily scalable across a broad performance range. To guard against this, the current policy relies on a combination of U.S. government and vendor efforts to monitor systems after shipment to ensure that they are in compliance. This simplifies the licensing process, but reliable post-shipment verification is difficult. An alternative approach is to consider the degree to which system performance can be scaled as part the license application review. Systems that are easily scalable without vendor support might be treated more strictly, especially if they are to go to Tier 3 countries.