China continues to dominate a list of the world's fastest supercomputers by the number of systems, according to a semiannual ranking of the Top 500 published Monday.

China tops the supercomputer list with 219 systems, the United States is second with 116 and Japan third with 29 systems, followed by France, Britain and Germany, according to the ranking.

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 US-built supercomputers Summit and Sierra retain the first two positions, both powered by IBM Power 9 CPUs and NVIDIA V100 GPUs.

The computers are so fast that their speed is measured in petaflops - or one thousand trillion operations per second.

The Summit delivered a record 148.6 petaflops, while Sierra system remained unchanged at 94.6 petaflops.

China's Sunway TaihuLight supercomputer, installed at the National Supercomputing Center in Wuxi, holds the third position with 93.0 petaflops.

China's Tianhe-2A (Milky Way-2A), deployed at the National Supercomputer Center in Guangzhou, remains No 4 on the list, achieving 61.4 petaflops.

Frontera, a US system installed at the Texas Advanced Computing Center of the University of Texas, was ranked fifth and was also 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.

Among the listed systems, those in the United States are on average more powerful, allowing the country to maintain its lead in overall capacity, with 38.4 percent of the aggregate list performance. China comes second, with 29.9 percent.

The Top 500 list is considered one of the most authoritative rankings of the world's supercomputers. It is compiled on the basis of machine performance on the Linpack bench mark by experts from the United States and Germany.

The Linpack bench mark is a software library for performing numerical linear algebra on digital computers, used to measure a supercomputer's real performance in practical use.

Xinhua