For years, chip companies like Intel have sold widely available microchips to supercomputer makers in China, even some with close ties to the military. In 2015, the Commerce Department moved to add China’s National University of Defense and Technology to the entity list, to cut it off from using Intel chips in supercomputers that the United States government said were being used to model nuclear detonations.
On Friday, the list was updated with a number of new addresses and names through which the National University of Defense Technology was procuring chips. According to China’s official list of its fastest supercomputers, the institute still runs two of China’s three fastest supercomputers on Intel processors.
In its current order, the Commerce Department highlights the next frontier in supercomputing: “exascale” machines, which China, the United States and other nations are racing to build. They will be five times as fast as the fastest machine today — the Summit, which is housed at Oak Ridge and was built by IBM in a partnership with Nvidia.
The Commerce Department order cites the three groups “leading China’s development of exascale high-performance computing”: Sugon, the Wuxi Jiangnan Institute of Computing Technology and the National University of Defense Technology.
These three companies are all developing prototype exascale machines in China that are powered by Chinese-made microprocessors, said Jack Dongarra, a supercomputer expert at the University of Tennessee and a co-creator of the Top 500 list of the swiftest machines.
But other key technologies in the fastest supercomputers will be affected. Supercomputers are made by lashing together thousands of processors, linked by a specialized fabric of digital circuitry known as interconnect technology. The leading producer of high-performance interconnect technology is Mellanox, an Israeli company that Nvidia agreed this year to buy for $6.9 billion.
“The interconnect technology is as important if not more important than the processors,” Mr. Dongarra said. “The impact of this government order is going to be far-reaching.”
It is likely to hamper the Chinese in the short run, he said, but also encourage China to redouble its efforts to replace American technology.