a. Minimaps d. 3D Slice

Abstract—Understanding the interactions between a parallel application and the interconnection network over which it ex-changes data is critical to optimizing performance in modern supercomputers. However, recent supercomputing architectures use networks that do not have natural low-dimensional repre-sentations, making them difficult to comprehend or visualize. In particular, high-dimensional torus networks are common and are used in four of the top ten supercomputers and eight of the top ten on the Graph500 list. We present a new visualization of five-dimensional torus networks. We use four connected views depict-ing the network at different levels of detail, allowing analysts to observe general large-scale traffic patterns while simultaneously viewing individual links or outliers in any specific section of the network. We demonstrate this approach by analyzing network traffic for a pF3D simulation running on the IBM Blue Gene/Q architecture, and show how it is both intuitive and effective for understanding and optimizing parallel application behavior. I