Spatio-temporal correlations and rollback distributions in optimistic simulations

In this paper we study the influence of spatio-temporal correlations on the dynamic runtime behavior of the optimistic parallel Time Warp simulation method. By using the Ising spin model, we show experimentally that the distribution of the number of rolled back events behaves as a power-law distribution over a large range of sub-critical Ising temperatures and decays exponentially or super-critical Ising temperatures. For critical Ising temperatures, where long-range correlations occur the computational complexity, of Time Warp and physical complexity of the Ising spin model are entangled and contribute both to the runtime behavior in a nonlinear way.