The US Department of Energy's Oak Ridge National Laboratory (ORNL) announced that its Frontier supercomputer ranked as the world's fastest supercomputer on the TOP500 list. In the previous two years, the position was held by the Fugaku system at the RIKEN Center for Computational Science in Kobe, Japan. Frontier is said to be the first machine to have passed the threshold of a quintillion calculations per second, thus achieving a level of performance known as exascale. According to ORNL, the supercomputer 'will enable scientists to develop critically needed technologies for the country's energy, economic and national security, helping researchers address problems of national importance that were impossible to solve just five years ago'. 
But is Frontier really the first machine to have achieved exascale performance? Some experts doubt it: Two systems in China might have gotten there faster, but their operators did not submit test results for evaluation in the TOP500 ranking, probably because of USA-China geopolitical tensions.