He [Jack Dongarra, director of the Innovative Computing Laboratory at the University of Tennessee at Knoxville] recently helped create a new speed test, one that considers many variables, called the
HPC challenge benchmark. It measures things like how fast data can be stored, retrieved, and moved within the computer. But the test is not as popular as the method used by the Top 500 list, although the NSF and other U.S. agencies have used it, he says. It doesn't produce a ranking, since there is no way to fairly reduce the variables to one number for comparative purposes—in the same way Consumer Reports doesn't produce a single ranking for all cars, he says. "I wouldn't want to make policy based on one number."
In November, still another supercomputer ranking was unveiled, at a conference in New Orleans. This one, called Graph500, does produce a ranking, but it is based on how fast supercomputers solve complex problems related to randomly generated graphs, rather than on the simpler computation of the Top 500. Some computers that had ranked well on the Top 500 ran the Graph500, but their operators refused to announce the scores, most likely because they fared less well.
Does that mean China may not actually be ahead in the supercomputing race? Hard to tell, unless its computers participate in alternative challenges to Top 500. One scientist here speculated that the Chinese computer may have been designed simply to do well on that one test.
Mr. Dongarra says he saw the Chinese machine when he visited China's National Supercomputing Center, about two hours' drive from Beijing. "It's state-of-the-art in many ways," he says, noting that he was impressed by the unique interconnections among processors that researchers there had developed.
Mr. Reed, of Microsoft Research, says he, too, has been impressed by China's efforts. "I used to say that in the high-performance computing race, the U.S. was laps ahead," he says. "Now it's steps ahead."
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