Tangential to his point, but N-Body simulations like this are almost a perfect fit for GPU computation. The power of modern GPU's is astonishing. It's probable

Tangential to his point, but N-Body simulations like this are almost a perfect fit for GPU computation. The power of modern GPU's is astonishing. It's probable that he could get his "about a day" calculations down to a few minutes, or alternatively, keep the runtime the same and dramatically improve the accuracy or length of simulation. Here's a couple of recent papers: Using Graphics Processing Units to solve the classical N-body problem in physics and astrophysics http://arxiv.org/abs/1411.5234 http://arxiv.org/abs/1411.5234 The GENGA Code: Gravitational Encounters in N-body simulations with GPU Acceleration http://arxiv.org/abs/1404.2324 http://arxiv.org/abs/1404.2324