Once the world’s most powerful supercomputer, the Titan at Oak Ridge National Laboratory dropped to number four on a list of the world’s most powerful supercomputers released earlier this week. The Titan, a Cray XK7 system, was bumped from the number three spot by the upgraded Piz Daint, a Cray XC50 system installed at the Swiss National Supercomputing Centre. China continues to have the world’s two most powerful supercomputers. The TOP 50 List of the world’s most powerful supercomputers is based on a benchmark test known as Linpack. The list is released twice each year, once in June and again in November. The 49th edition of the TOP 500 List was released Monday in conjunction with the opening session of the ISC High Performance conference, which is taking place this week in Frankfurt, Germany.