Blue Waters Symposium 2019

The focus of this talk is on improving simulation performance by exposing algorithms to machine layout, as found in modern machines such at Blue Waters. The solution to large sparse linear systems, for example, often demands a high amount of communication. By reorganizing the communication in a node-centric manner, the number of costly intranode messages can be reduced. The talk will highlight the benefits of using node aware communication in the context of a multigrid solver. The solve times can be reduced in comparison to conventional approaches. The results also extend to a wider range of sparse matrix operations and a general communication package will be presented.