New York

AMERICA is now home to the world's speediest supercomputer. But the new list of the 500 swiftest machines underlines how much faster China is building them.

The list, published Monday, shows the Chinese companies and government pulling away as the most prolific producer of supercomputers, with 206 of the top 500.

American corporations and the US government designed and made 124 of the supercomputers on the list. For years, the United States dominated the supercomputer market. But two years ago, China pulled even on the Top 500 list. China moved decisively ahead last fall and extended the gap in the latest tally.

Making the most powerful supercomputers is regarded as one measure of a nation's technical prowess, even if they are a rarefied niche of technology. Countries and companies have increasingly deployed the machines in a wider range of tasks in fields including medicine, new materials and energy technology.

Supercomputing is one step in China's rapid rise in technology, stirring concerns in America about the country's grand plan and tactics - and the potential economic and geopolitical implications of those advancements.

In an assessment last fall, the US-China Economic and Security Review Commission, a bipartisan congressional advisory group, pointed to supercomputing as part of China's "ambitious whole-of-government plan to achieve dominance in advanced technology".

China began its supercomputing push in earnest a decade ago. Initially, it absorbed foreign technology, and then steadily developed its own. "China was slow to make that work, but it's working now," said Richard Suttmeier, an expert in Chinese science policy at the University of Oregon.

The high-performance computing program, policy experts say, offers a blueprint for the multibillion-dollar efforts China has recently begun in fields such as artificial intelligence and quantum computing - the next frontiers of technology, where economic advantages will be won or lost.

Supercomputer technology has occasionally been a trade issue between the United States and China. In 2015, for example, Washington denied Intel a licence to sell its microprocessor chips to four supercomputer labs in China, saying the centres worked on technology for the Chinese military.

The export ban, supercomputer experts say, served to prod the Chinese to accelerate their development efforts. "The lesson the Chinese took away was that you can't rely on the United States," said Jack Dongarra, a supercomputer expert at the University of Tennessee and co-creator of the Top 500 list of the fastest machines. "They're trying to replace all Western technology with all Chinese-made."

Supercomputers were once found almost entirely in national laboratories, and used for government projects such as simulating nuclear explosions and modelling weather patterns. But more than half the 500 fastest are now toiling for corporations.

The global supercomputer market is expected to double from 2017 to 2022, to more than US$9.5 billion, according to an estimate from Hyperion Research. The research firm defines supercomputers as machines that cost more than US$500,000 each. Three Chinese companies are among the top five makers of the 500 fastest supercomputers. Lenovo is first, Inspur is third, and Sugon is fifth. Two US companies are second and fifth, Hewlett-Packard Enterprise and Cray.

The new list confirmed that the current fastest machine resides in the United States. This month, the Department of Energy announced that its new supercomputer, called Summit, had achieved speeds well ahead of the previous leader, the Sunway TaihuLight at a Chinese supercomputing centre in Wuxi. Summit, built by IBM in partnership with Nvidia, is at the Oak Ridge National Laboratory in Tennessee.

Qian Depei, a top supercomputer researcher in China, marvels at the progress his nation has made in the past decade - "beyond our expectations". he said. A point of particular pride: The Sunway TaihuLight machine uses homegrown microprocessors. "That used to be a weakness," said Prof Qian, a computer science professor at both Sun Yat-sen University and Beihang University.

But while China has made impressive strides, he said the country still lagged in certain advanced hardware technologies and, especially, in software. "Software is a tough issue for us," he said. "That will take longer."

The 500 list is based on the machines' speed of mathematical calculation. NYTIMES