Fractal Communication in Software Data Dependency Graphs

Communication is increasingly more costly than computation, but little work has been done on characterising the intrinsic communication behaviour of algorithms. We show that the dynamic data dependency graphs for a wide number of benchmarks exhibit multi-scale fractal communication. This has important implications for the locality of NoC communication in a CMP as well as for temporal locality. Benchmarks that do not exhibit fractal scaling or that have high fractal dimensionality may have poor communication scalability on a CMP.