Cholesky factorizations for multi-core systems

Jonathan Hogg ( Rutherford Appleton Laboratory )

Multicore chips are nearly ubiquitous in modern machines, and to fully exploit this continuation of Moore's Law, numerical algorithms need to be able to exploit parallelism. We describe recent approaches to both dense and sparse parallel Cholesky factorization on shared memory multicore systems and present results from our new codes for problems arising from large real-world applications. In particular we describe our experiences using directed acyclic graph based scheduling in the dense case and retrofitting parallelism to a sparse serial solver.