Area and power savings via asymmetric organization of buffers in 3D-NoCs for heterogeneous 3D-SoCs

In this paper we investigate the effects of asymmetric organization and depths of Network-on-Chip (NoC) router buffers among dies in heterogeneous 3D-System-on-Chips (SoCs). In our novel approach the properties of the routers are aligned with the characteristics of the technological nodes per layer. We call these designs Asymmetric 3D-NoCs (A-3D-NoCs). In this work we demonstrate potentials of A-3D-NoCs in comparison to a conventional, symmetric 3D-NoC: Applying asymmetric buffer reorganization we achieve area savings of 8.3% and power savings of 5.4% for link buffers while accepting a minor average system performance loss of 2.1%. With additional asymmetry in buffer depth up to 28% cost savings and 15% power reduction are given in combination with a 4.6% performance decline. Thus, the proposed buffer organization scheme is applicable for cost and power critical applications of NoCs in heterogeneous 3D-SoCs.