China continues to dominate a list of the world’s fastest supercomputers by the number of systems, according to a semi-annual ranking of the TOP500. China tops the supercomputer list with 219 systems, or 43.8% of the total, followed by the United States with 116, Japan third with 29 systems, followed by France, Britain and Germany. Major Chinese supercomputer vendors all improved their shares from six months ago. Lenovo claims the greatest number of systems on the list with 173, followed by Inspur with 71 and Sugon with 63.

The top of the list remained largely unchanged. Two U.S.-built supercomputers, Summit and Sierra, retain the first two positions, both powered by IBM Power 9 CPUs and NVIDIAV100 GPUs. The Summit delivered a record of 148.6 petaflops on the High Performance Linpack (HPL) test. China’s Sunway TaihuLight supercomputer at the National Supercomputing Center in Wuxi holds the third position with 93.0 petaflops. China’s Tianhe-2A (Milky Way-2A) at the National Supercomputer Center in Guangzhou is No 4 on the list. Frontera, a U.S. system at the Texas Advanced Computing Center of the University of Texas, is the only newcomer in the top 10.

For the first time in the 26-year history of the ranking, all systems that made the list are petaflop systems. Those in the United States are on average more powerful, allowing the country to maintain its lead in overall HPL capacity, with 38.4% of the aggregate list performance. China comes second, with 29.9% of the total, the Shanghai Daily reports.

The U.S. Commerce Department said it was adding five Chinese companies and a government-owned institute involved in supercomputing with military applications to its national security “entity list,” which bars them from buying U.S. parts and components without government approval. The department said it was adding Sugon, the Wuxi Jiangnan Institute of Computing Technology, Higon, Chengdu Haiguang Integrated Circuit, and Chengdu Haiguang Microelectronics Technology to the list over concerns about the military applications of the supercomputers they are developing.

The Commerce Department said the companies “pose a significant risk of being or becoming involved in activities contrary to the national security and foreign policy interests of the United States.”The Wuxi Jiangnan Institute of Computing Technology is owned by the 56th Research Institute of the General Staff of China’s People’s Liberation Army (PLA), the Commerce Department said, adding “its mission is to support China’s military modernization”, the China Economic Review reports.