A work- and data-sharing parallel tree N-body code

We describe a new parallel N-body code for simulations of the formation and evolution of the large-scale structure of the Universe. The code is based on a work- and data-sharing scheme, and is implemented within the Gray Research Corporation's CRAFT(C) programming environment. Different data distribution schemes have been adopted for bodies' and tree's structures. Tests performed for two different types of initial distributions show that the performance scales almost ideally as a function of the size of the system and of the number of processors. We discuss the factors affecting the absolute speed-up and how it can be increased with a better tree's data distribution scheme.