title: Evaluating the performance of parallel subsurface simulators: An illustrative example with PFLOTRAN.
abstract: [1] To better inform the subsurface scientist on the expected performance of parallel simulators, this work investigates performance of the reactive multiphase flow and multicomponent biogeochemical transport code PFLOTRAN as it is applied to several realistic modeling scenarios run on the Jaguar supercomputer. After a brief introduction to the code's parallel layout and code design, PFLOTRAN's parallel performance (measured through strong and weak scalability analyses) is evaluated in the context of conceptual model layout, software and algorithmic design, and known hardware limitations. PFLOTRAN scales well (with regard to strong scaling) for three realistic problem scenarios: (1) in situ leaching of copper from a mineral ore deposit within a 5-spot flow regime, (2) transient flow and solute transport within a regional doublet, and (3) a real-world problem involving uranium surface complexation within a heterogeneous and extremely dynamic variably saturated flow field. Weak scalability is discussed in detail for the regional doublet problem, and several difficulties with its interpretation are noted.
authors.affiliation: Applied Systems Analysis and Research, Sandia National Laboratories Albuquerque, New Mexico, USA.
authors.forename: G E
authors.initials: GE
authors.lastname: Hammond
authors.affiliation: OFM Research Santa Fe, New Mexico, USA.
authors.forename: P C
authors.initials: PC
authors.lastname: Lichtner
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory Oak Ridge, Tennessee, USA ; Electrical Engineering and Computer Science and Earth and Planetary Sciences Departments, University of Tennessee Knoxville, Tennessee, USA.
authors.forename: R T
authors.initials: RT
authors.lastname: Mills
keywords: biogeochemical transport; groundwater flow; high performance computing