Building supercomputers is a digital arms race, and China is moving quickly to solidify its lead. Last year, the country unveiled the world’s fastest supercomputer, the Sunway TaihuLight (above). This year, according to state news agency Xinhua, the government has set its sights on completing the world’s first prototype exascale computer; a machine capable of making a billion billion calculations per second.

What’s a FLOP? The power of supercomputers is commonly measured in FLOPS or “floating point operations per second.” The greater the number of FLOPS a computer can calculate, the more powerful it is. Right now, the fastest supercomputers in the world can make quadrillions — or thousands of trillions — calculations each second. Using the standard system of metric measurement, a quadrillion is referred to using the prefix “peta.” So, the speed of these computers is calculated in petaflops, and computers operating at this level are referred to as petascale machines. Following this system of prefixes, the next step up from “peta” is “exa” — meaning a quintillion or a billion billion. A computer that can compute this number of calculations each second is measured in exaflops and is said to be an exascale machine.

The prototype computer will be ready before the end of the year, said Zhang Ting, an engineer at the country’s National Supercomputer Center, but the finished product won’t be operational for several years more. “A complete computing system of the exascale supercomputer and its applications can only be expected in 2020,” said Zhang. “[It] will be 200 times more powerful than the country's first petaflop computer Tianhe-1, recognized as the world's fastest in 2010.”

It’s not clear exactly how this prototype system will relate to the finished exascale computer in terms of capability, but the news suggests China will at least be first to reach such a milestone. A number of nations — including Japan and the US — are planning to build exascale computers. The US Department of Energy says its current schedule is to have an exsacale system operational by 2023.

As of last June, China has more supercomputers in the world’s top 500 than the US — 167 compared to 165. (The US has more machines in the top 10 though; five to China’s two.) These systems are used for a number of tasks, ranging from life sciences to national defense. In 2015, the US actually blocked the export of Intel chips to China for its then-fastest supercomputer, fearing that the machine would be used for nuclear research. China instead built an even faster system (the Sunway TaihuLight) using its own processors instead.