China has unveiled one of its secret top-performing supercomputers, which was built under U.S. sanctions. Powered by an upgraded home-grown chip, the new Sunway OceanLight supercomputer boasts a performance that is second only to the world’s most powerful system – the Frontier – which was built and hosted by the U.S. Department of Energy’s Oak Ridge National Laboratory. According to a Chinese computer scientist who asked not to be named, the new Sunway is not the most powerful supercomputer in China at present. But after details of it were revealed at the Supercomputing 2023 (SC23) conference in Denver (U.S.), earlier this month, it gave the public some hints on how China has managed to sidestep U.S. sanctions to build its own supercomputers. While the home-grown chips the new Sunway uses are not as powerful as in the U.S. version, the Chinese scientists have instead increased the number of CPU cores to more than 41 million – nearly five times as many as Frontier. This does, however, increase energy consumption, size and cost of running the supercomputer. But despite the drawbacks of the measures needed to circumvent the U.S. sanctions, the result is a fast and powerful machine.
The supercomputer has a speed of a billion billion operations per second, expressed as 5 exaflops under a benchmark called “HPL mixed precision”, a technical way of measuring the performance of supercomputers. Frontier has a score of 9.95 exaflops. This Chinese dark horse has outdone leading supercomputers, including the Frontier, in computing efficiency. It can maintain over 85% of its peak performance in regular operation, ranking the highest among all heterogeneous systems – a type of common supercomputing architecture – and second among all systems.
Meanwhile, China’s most powerful supercomputer remains undisclosed and other supercomputing chips are also under development, according to the Chinese scientist who works at a top Chinese university. The new OceanLight is an iteration of the Sunway TaihuLight, developed by the National Research Center of Parallel Computer Engineering and Technology in Wuxi in Jiangsu province. TaihuLight was once number one on the Top500 list of supercomputers, the most influential ranking of the 500 fastest supercomputer systems in the world. It held the top spot from 2016 to 2018 but fell to 11th place in the latest ranking.
This new generation of Sunway is made possible largely because it is underpinned by a more powerful processor, the Sunway SW26010 Pro CPU, which is an upgraded version of the Sunway SW26010 that was used in the TaihuLight system. Compared with its predecessor, the new processor has made improvements in clock speed, the instruction set and the memory bandwidth, leading to a fourfold increase in performance. The SW26010-Pro was a home-grown chip that aimed to boost China’s supercomputing capabilities and self-reliance, but it was still not on a par with its most advanced rivals, scientists said. To get around that, in the new Sunway system, Chinese scientists have employed a strategy where, despite the inferior individual chips, they use a greater number of cores to enhance the computer’s performance. “The sanctions on chips make it expedient for China’s supercomputers to rely on more cores to achieve the same results,” a scientist said, as reported by the South China Morning Post.
