China holds the top two spots for fastest computers in the world, and Switzerland holds the third, with the U.S. in the fourth, fifth and sixth spots.The Top500 list of the most powerful supercomputers in the world was released at the 2017 International Supercomputing Conference in Frankfurt, Germany.But the U.S. might not miss its top spot for long. The Department of Energy awarded six companies a total of $258 million last Thursday to further the research and development of the world’s first exascale supercomputer. There are no computers that powerful today.The U.S. formerly held the third spot, but this time it was edged out by a system from the Swiss National Supercomputing Centre, which moved up from eighth place. This is only the second time in 24 years of compiling the Top500 list that the U.S. did not have a computer place in one of the top three positions.These computers process at petascale speeds, meaning their capabilities are measured in terms of one quadrillion (1,000,000,000,000,000) calculations per second. To put that in perspective, consumer laptops now operate at gigascale, which is one billion calculations per second.An exascale computer is capable of processing a quintillion (1,000,000,000,000,000,000) calculations per second. That’s about a trillion times more powerful than a consumer laptop.Exascale-level computing would allow scientists to make extremely precise digital simulations of biological systems, which could uncover answers to pressing questions like climate change and growing food that can withstand drought.The more powerful the computer, the more realistic the models are, which in turn provide scientists with more reliable predictions about the future and more concrete recommendations about what companies and governments need to do.Here’s a list of the Top 10 most powerful supercomputers in the world. The U.S. holds the most spots on the list, with five supercomputers that made the cut.1. Sunway TaihuLight — China2. Tianhe-2 (MilkyWay-2) — China3. Piz Daint — Switzerland4. Titan — United States5. Sequoia — United States6. Cori — United States7. Oakforest-PACS — Japan8. K Computer — Japan9. Mira — United States10.Trinity — United States