Seminars at the Faculty of Informatics

Extending Strong-Scaling Limits with PFASST

The Faculty of Informatics is pleased to announce a seminar given by Dr. Robert Speck

DATE: Thursday, March 27th, 2014
PLACE: University of Lugano, room 402, main building, 4th floor (Via G. Buffi 13)
TIME: 10:30

ABSTRACT:
The challenges arising from the extreme levels of parallelism required by todays and future HPC systems mandates the mathematical development of new numerical methods featuring a maximum degree of concurrency.
Iterative time integration methods that can provide parallelism along the temporal axis have become increasingly popular over the last years.
The recently developed "parallel full approximation scheme in space and time" (PFASST) can integrate multiple time-steps simultaneously in a multigrid-fashioned way.
Based on multilevel spectral deferred corrections (MLSDC), PFASST is able to apply multiple coarsening strategies in space and time. Here, careful balancing between aggressive coarsening and fast convergence is necessary.
In this talk, we will discuss various, application-tailored coarsening strategies and show recent results on successful combinations of space-parallel solvers with PFASST.
We will highlight extreme-scale benchmarks with a multigrid solver on up to 448K cores of the IBM Blue Gene/Q installation JUQUEEN and describe ongoing work on developing a space-time parallel tree code for plasma physics applications using a multilevel, high-order Boris integrator.

BIO:
Since 2012: Postdoc at Juelich Supercomputing Centre
Since 2011: Postdoc at Institute of Computational Science, USI, Lugano
2011: PhD at University of Wuppertal
2007: Diploma in Applied Mathematics at University of Trier

HOST: Dr. Daniel Ruprecht