FIGURE 7.1 TOP500 by country.

decade: No particular trend emerges, except the progressive broadening of the “other” category, indicating the progressive democratization of supercomputing, attributable to the advent of relatively low cost commodity clusters.

The dominance is even more striking when one looks at manufacturers: 91 percent of the TOP500 systems are manufactured in the United States (see Figure 3.7). Many of the remaining systems use U.S.-manufactured commodity parts. The software stack of supercomputing systems used worldwide (operating systems, compilers, tools, libraries, application codes, etc.) was also largely developed in the United States, with significant contributions from researchers in other countries.

However, this is no reason for complacency. Since late 2001, the system that heads the TOP500 list has been the Earth Simulator (ES), installed in Japan. Even more important than being the most powerful system, the ES, because of its use of custom vector processors, achieves higher sustained performance on application codes of interest than many of the other top-performing machines. While the ES is likely to lose its top position on