Are Uniform Nerworks Scalable?

Parallel computers essentially employ interconnection networks. Huge-scale systems require appropriate networks that can correspond to their required performance. This paper addresses a scalability issue of uniform interconnection networks. We first propose an evaluation method suitable to large-scale networks, define critical load ratio as a common measure, and introduce introduce ramp-, step-, and impulse responses. Our evaluation results reveal some new knowledge on large-scale networks: (1) performance is scalable from macro-scopic viewpoint, (2) large-scale network is sensitive to congestion and sometimes complex behaviors emerge.