High Performance Gravitational N-body Simulations on a Planet-wide
  Distributed Supercomputer
  We report on the performance of our cold-dark matter cosmological N-body
simulation which was carried out concurrently using supercomputers across the
globe. We ran simulations on 60 to 750 cores distributed over a variety of
supercomputers in Amsterdam (the Netherlands, Europe), in Tokyo (Japan, Asia),
Edinburgh (UK, Europe) and Espoo (Finland, Europe). Regardless the network
latency of 0.32 seconds and the communication over 30.000 km of optical network
cable we are able to achieve about 87% of the performance compared to an equal
number of cores on a single supercomputer. We argue that using widely
distributed supercomputers in order to acquire more compute power is
technically feasible, and that the largest obstacle is introduced by local
scheduling and reservation policies.
