Speaker
Dr
Sebastian von Alfthan
(CSC)
Description
Vlasiator is a 6D hybrid-Vlasov simulation code, that has
been developed for simulating Earth's magnetosphere at
kinetic scales. Here I will present some of the key techniques
used for enabling current 5D simulations on Petascale
machines, and also present some of the ongoing
development efforts. In particular I will present the semi-
Lagrangian solver used for propagating the Vlasov fluid, and
describe the sparse representation that enables 5D
simulations by reducing the problem size by orders of
magnitude. I will also discuss current work on a new
heterologous domain decomposition, in which the spatial
domain of one mpi task is not identical for the field- and
Vlasov solvers. Solving the two problems on separate grids
allows load balancing to be performed separately and
overcome the previously existing scaling problems. Finally I
will also discuss experiences in porting Vlasiator to the Xeon
Phi processor (Knights Landing), and share experience in
running large scale simulations on a large Xeon Phi based
supercomputer (Marconi).
