Titre : An efficient parallel local search algorithm Exposant : Florian Richoux Résumé : We present a parallel constraint-based local search algorithm and its implementation. We investigate its performance results for hard combinatorial optimization problems on two different massively parallel platforms up to several hundreds of cores. On a variety of classical CSP benchmarks, speedups are very good for a few tens of cores, and good up to a hundred cores. More challenging problems derived from real-life applications (Costas array) show nearly linear speedups up to 8,192 cores on a third platform. To achieve these results, we use a simple parallel scheme with the strict minimum number of communications. We will also present some more complex parallel schemes with communicating processes sharing information about the search procedure.