Atmosphere and ocean models are characterised by complex dependencies, external configurations, a... more Atmosphere and ocean models are characterised by complex dependencies, external configurations, and performance requirements. The objective to containerise such software stacks helps to provide a consistent environment to ensure security, portability and performance. Since the container is built only once, but then can be deployed on multiple platforms, productivity is increased. ETH Zurich (ETHZ) has organised and carried out a "hackathon" (programming session) to help ESiWACE community scientists create containers for their Earth-system models. Seven teams joined the hackathon, and each team was assigned a mentor with extensive container experience. The teams were given the challenge to get as far as they could in containerising their model, and, if possible, to analyse performance at scale on the Piz Daint computing platform at the Swiss National Supercomputing Centre (CSCS). The teams made faster progress on their containers than even we organisers anticipated. Althoug...
The COSMO-CLM model, originally developed by Deutscher Wetterdienst, is a non-hydrostatic regiona... more The COSMO-CLM model, originally developed by Deutscher Wetterdienst, is a non-hydrostatic regional atmospheric model which can be used for numerical weather prediction and climate simulations and is now in use by a number of weather services for operational forecasting (e.g. MeteoSwiss). One current software engineering goal is to improve its scaling characteristics on multicore architectures by making it a hybrid MPI-OpenMP code. We will present hybridization strategies for different components of the model, show some first performance results, and discuss the impact on further development of the model.
Proceedings of the 1997 ACM/IEEE conference on Supercomputing (CDROM) - Supercomputing '97, 1997
This presentation discusses the NASA data assimilation project at the Data Assimilation Office at... more This presentation discusses the NASA data assimilation project at the Data Assimilation Office at the NASA/Goddard Space Flight Center. The goal is to produce accurate gridded datasets of atmospheric fields by assimilating a range of observations along with physically consistent model forecasts. This work produces datasets that are used by the climate research community. The data come from conventional sources
In this paper we investigate the energy footprint and performance profiling of COSMO-ART on vario... more In this paper we investigate the energy footprint and performance profiling of COSMO-ART on various HPC platforms. This model is an extension of the operational weather forecast model of the German...
ETH/CSCS has the duty of providing stable computing resources for its customers' applications... more ETH/CSCS has the duty of providing stable computing resources for its customers' applications. In climate research this requirement often requires stable, reproducible execution of a particular application over multiple years. Since the underlying computing platform – in our case CSCS Piz Daint – changes with each upgrade, ensuring such continuity for users is at best challenging. ESiWACE2 is putting a large effort to evaluate containers to see if they provide the platform stability needed. The object of this milestone, <em>One model ported using containers, </em>is to illustrate first-hand the viability of the container paradigm. The PRACE-supported QUBICC project which uses the Icosahedral Non-hydrostatic (ICON) model to simulate the evolution of the atmosphere in order to analyse the quasi-biennial oscillation (QBO) – the roughly 2-year shift from prevailing westerly mean flow to easterly and back – is one such application. The underlying high global resolution (2...
Abstract. The Earth System Modeling Framework (ESMF) project is developing a standard software pl... more Abstract. The Earth System Modeling Framework (ESMF) project is developing a standard software platform for Earth system models. The standard defines a com-ponent architecture superstructure and a support infrastructure. The superstructure allows earth scientists to develop ...
We introduce an efficient and scalable parallel implementation of tight-binding molecular dynamic... more We introduce an efficient and scalable parallel implementation of tight-binding molecular dynamics which employs reordering of the atoms. This implementation also exploits the sparse character of the Hamiltonian matrix. Reordering allows our algorithm to scale well on parallel machines since it asssures data locality. A sparse storage format and a stabilized parallel Lanczos eigensolver allow consideration of large problem sizes
The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System... more The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System Model (CCSM) and is the primary consumer of computer resources in typical CCSM simulations. Performance engineering has been an important aspect of CAM development throughout its existence. This paper briefly summarizes these efforts and their impacts over the past five years.
International Journal of High Performance Computing Applications, 2005
We present a distributed memory message passing parallel implementation of a finite-volume discre... more We present a distributed memory message passing parallel implementation of a finite-volume discretization of the primitive equations in the Community Atmosphere Model. Due to the data dependences resulting from the polar singularity of the latitude-longitude coordinate system, we employ two separate domain decompositions within the dynamical core: one in latitude/level space and the other in longitude/latitude space. This requires that the data be periodically redistributed between these two decompositions. In addition, the domains contain halo regions that cover the nearest-neighbor data dependences. A combination of several techniques, such as one-sided communication and multithreading, are presented to optimize data movements. The resulting algorithm is shown to scale to very large machine configurations, even for relatively coarse resolutions.
Atmosphere and ocean models are characterised by complex dependencies, external configurations, a... more Atmosphere and ocean models are characterised by complex dependencies, external configurations, and performance requirements. The objective to containerise such software stacks helps to provide a consistent environment to ensure security, portability and performance. Since the container is built only once, but then can be deployed on multiple platforms, productivity is increased. ETH Zurich (ETHZ) has organised and carried out a "hackathon" (programming session) to help ESiWACE community scientists create containers for their Earth-system models. Seven teams joined the hackathon, and each team was assigned a mentor with extensive container experience. The teams were given the challenge to get as far as they could in containerising their model, and, if possible, to analyse performance at scale on the Piz Daint computing platform at the Swiss National Supercomputing Centre (CSCS). The teams made faster progress on their containers than even we organisers anticipated. Althoug...
The COSMO-CLM model, originally developed by Deutscher Wetterdienst, is a non-hydrostatic regiona... more The COSMO-CLM model, originally developed by Deutscher Wetterdienst, is a non-hydrostatic regional atmospheric model which can be used for numerical weather prediction and climate simulations and is now in use by a number of weather services for operational forecasting (e.g. MeteoSwiss). One current software engineering goal is to improve its scaling characteristics on multicore architectures by making it a hybrid MPI-OpenMP code. We will present hybridization strategies for different components of the model, show some first performance results, and discuss the impact on further development of the model.
Proceedings of the 1997 ACM/IEEE conference on Supercomputing (CDROM) - Supercomputing '97, 1997
This presentation discusses the NASA data assimilation project at the Data Assimilation Office at... more This presentation discusses the NASA data assimilation project at the Data Assimilation Office at the NASA/Goddard Space Flight Center. The goal is to produce accurate gridded datasets of atmospheric fields by assimilating a range of observations along with physically consistent model forecasts. This work produces datasets that are used by the climate research community. The data come from conventional sources
In this paper we investigate the energy footprint and performance profiling of COSMO-ART on vario... more In this paper we investigate the energy footprint and performance profiling of COSMO-ART on various HPC platforms. This model is an extension of the operational weather forecast model of the German...
ETH/CSCS has the duty of providing stable computing resources for its customers' applications... more ETH/CSCS has the duty of providing stable computing resources for its customers' applications. In climate research this requirement often requires stable, reproducible execution of a particular application over multiple years. Since the underlying computing platform – in our case CSCS Piz Daint – changes with each upgrade, ensuring such continuity for users is at best challenging. ESiWACE2 is putting a large effort to evaluate containers to see if they provide the platform stability needed. The object of this milestone, <em>One model ported using containers, </em>is to illustrate first-hand the viability of the container paradigm. The PRACE-supported QUBICC project which uses the Icosahedral Non-hydrostatic (ICON) model to simulate the evolution of the atmosphere in order to analyse the quasi-biennial oscillation (QBO) – the roughly 2-year shift from prevailing westerly mean flow to easterly and back – is one such application. The underlying high global resolution (2...
Abstract. The Earth System Modeling Framework (ESMF) project is developing a standard software pl... more Abstract. The Earth System Modeling Framework (ESMF) project is developing a standard software platform for Earth system models. The standard defines a com-ponent architecture superstructure and a support infrastructure. The superstructure allows earth scientists to develop ...
We introduce an efficient and scalable parallel implementation of tight-binding molecular dynamic... more We introduce an efficient and scalable parallel implementation of tight-binding molecular dynamics which employs reordering of the atoms. This implementation also exploits the sparse character of the Hamiltonian matrix. Reordering allows our algorithm to scale well on parallel machines since it asssures data locality. A sparse storage format and a stabilized parallel Lanczos eigensolver allow consideration of large problem sizes
The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System... more The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System Model (CCSM) and is the primary consumer of computer resources in typical CCSM simulations. Performance engineering has been an important aspect of CAM development throughout its existence. This paper briefly summarizes these efforts and their impacts over the past five years.
International Journal of High Performance Computing Applications, 2005
We present a distributed memory message passing parallel implementation of a finite-volume discre... more We present a distributed memory message passing parallel implementation of a finite-volume discretization of the primitive equations in the Community Atmosphere Model. Due to the data dependences resulting from the polar singularity of the latitude-longitude coordinate system, we employ two separate domain decompositions within the dynamical core: one in latitude/level space and the other in longitude/latitude space. This requires that the data be periodically redistributed between these two decompositions. In addition, the domains contain halo regions that cover the nearest-neighbor data dependences. A combination of several techniques, such as one-sided communication and multithreading, are presented to optimize data movements. The resulting algorithm is shown to scale to very large machine configurations, even for relatively coarse resolutions.
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Papers by William Sawyer