LANS Informal Seminar: Jed Brown

Seminar Title: On Time Integration for Strong Scalability
Speaker: Jed Brown, Assistant Professor, Computer Science, University of Colorado Boulder

Date/Time: 2019-07-17 10:30
Location: Bldg. 240, Rm. 1404-05

Description:
Modern computer architecture is characterized by increasing compute capacity (via vectorization and intranode parallelism) and modest improvements in network and DRAM bandwidth while latency has remained nearly constant.  As a result, the prospects for PDE-based simulation to reduce time to solution are poor when using current algorithms.  We consider a collection of related numerical methods and implementation techniques for shortening the critical path of accurate and stable transient simulation as a way to improve strong scalability and reduce memory bandwidth demands.  This approach unifies some “parallel in time” methods in terms of diagonal Runge-Kutta schemes, achieve different tradeoffs in the multi-objective Pareto front of {accuracy, time, cost}, and confronts numerical stability challenges.  We consider several implementation strategies and include a preliminary evaluation of the methods in the context of stiff and non-stiff PDEs.