U.S. efforts to build next-gen supercomputer take shape

For decades, the U.S. took for granted the doubling of supercomputing power every 10 years, roughly in line with Moore's Law. But once a petascale system was reached in 2008, it gradually became clear that the next leap -- a system 1,000 times more powerful -- would be difficult.
Initially, some believed such a system -- an exascale computer -- was possible in 10 years, or by 2018. But problems emerged. It took too much power, and it required new approaches to applications to utilize an almost