Breaking Rent's Rule: Opportunities for 3D Interconnect Networks

摘要

Stochastic estimates of wire-length based on Rent's rule predict a benefit of 3D integration overrntraditional ICs, tapering off with a 50% reduction for 8 tiers. However, Rent's rule is unnecessarily pessimistic, because it assumes an extrapolation of architectures that were conceived in two dimensions. This paper examines the gains possible in several 3D interconnect network topologies. Placement experiments with a 64-node 3-cube network show that a 75% reduction is possible with 4 tiers, and larger gains are possible with larger networks. Architectures for systems limited by nearest-neighbor communication are discussed, which are likely to show the most benefit from 3D integration.