Publica
Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. Multithreaded direction preserving preconditioners
 Muntean, T. ; Institute of Electrical and Electronics Engineers IEEE; IEEE Computer Society: ISPDC 2014, IEEE 13th International Symposium on Parallel and Distributed Computing. Proceedings : 2327 June 2014, Marseilles, France Los Alamitos, Calif.: IEEE Computer Society Conference Publishing Services (CPS), 2014 ISBN: 9781479959181 ISBN: 9780769552651 S.148155 
 International Symposium on Parallel and Distributed Computing (ISPDC) <13, 2014, Marseilles> 

 Englisch 
 Konferenzbeitrag 
 Fraunhofer ITWM () 
Abstract
The scalability and robustness of a class of nonoverlapping domain decomposition preconditioners using 2way nested dissection reordering is studied. We consider two different factorizations: nested and block versions. Both these variants have advantages and disadvantages. The nested variants have less than half the memory requirements compared to block variants. On the other hand, the block variants have faster solve phase and converges within similar number of iterations. In particular, four methods are considered: a nested symmetric successive over relaxation (NSSOR), its block variant block SSOR (BSSOR), nested filtering factorization (NFF), and its block variant block filtering factorization (BFF). The recently introduced filtering preconditioners namely NFF and BFF are two filtering preconditioners that preserve direction on a given filter vector. The scalability and robustness of these methods are discussed on shared memory architecture. We outline the algorithmic differences between NFF and BFF. The implementation is recursive and cache oblivious. The test cases consist of a Poisson problem and convectiondiffusion problems with jumping coefficients.