The Top Ten Supercomputer in the World

1 – Tianhe-2: Holed-up in China's National University of Defence Technology in Guangzhou, Tianhe-2 is the world's top system with a performance of 33.86 petaflops. Achieving quadrillions of calculations per second, Tianhe-2 uses Intel Xeon Phi processors and is named after the Milky Way.

2 – Titan: A Cray XK7 system at the US Department of the Oak Ridge National Observatory in Oak Ridge, Tenessee, It uses Nvidia Tesla GPUs and AMD Opteron CPUs to create a 17.5 petaflop system for a range of science projects. Titan will be replaced in 2018 by IBM's Summit.

3 – Sequoia: A former top-ranker, this monster-sized computer at the Lawrence Berkeley National Laboratory in Berkeley, California, concentrates on extending the life of ageing nuclear weapons and conducting experiments on nuclear fusion. It can sustain 17.1 petaflops via its 96-rack IBM Blue Gene/Q system.

4 – K computer: Japan's highest-ranking HPC, Fujitsu's K computer sits in Kobe, Japan's RIKEN Advanced Institute for Computational Science, where the machine uses its 10.5 petaflops to "solve the energy, sustainability, healthcare, climate change, industrial and space challenges facing society today".

5 – Mira: Another IBM Blue Gene/Q machine, the Mira supercomputer at Argonne National Laboratory, Lemont, Illinois, is owned by the US Department of Energy (DOE). It's among the most energy efficient, and gets to 8.58 petaflops.

IBM's Mira works for the US Department of Energy

6 – Piz Daint: Named after a mountain in the Swiss Alps and housed at the Swiss National Supercomputing Centre, this mighty Cray XC30 system uses its 6.27 petaflops primarily for climate and weather modelling, though also for astrophysics, materials science and life science.

7 – Stampede: This Dell-made 5.1 petaflops system at the Texas Advanced Computing Center, Austin, makes its 10 trillion operations per second available for open research, with projects including drug molecule construction to weather forecasting to astrophysics passing through its 462,462 cores.

8 – Juqueen: With its 458,752 cores, this IBM BlueGene/Q example boasts 5 petaflops and does neuroscience, computational biology, climate research and quantum physics at the Forschungszentrum Juelich. It's Germany's only entry in the top ten.

9 – Vulcan: Almost identical to the Juqueen, this Sequoia IBM BlueGene/Q system runs 4.29 petaflops at the Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The LLNL just inked a contract with IBM, Nvidia and Mellanox for a new supercomputer called Sierra for 2017, which will improve nuclear weapons modelling and do away with the need for underground testing.

10 – *Top secret*: We know it's based on a Cray CS-Storm system and achieves a paltry (for the top ten, anyhow) 3.57 petaflops, but this US government-owned supercomputer lacks the usual kooky name, and its whereabouts isn't publicly known. It's the most efficient HPC yet.