TIMELY COMMUNICATION A RESTRICTED ADDITIVE SCHWARZ PRECONDITIONER FOR GENERAL SPARSE LINEAR SYSTEMS

Abstract. We introduce some cheaper and faster variants of the classical additive Schwarz pre-conditioner (AS) for general sparse linear systems and show, by numerical examples, that the new methods are superior to AS in terms of both iteration counts and CPU time, as well as the communi-cation cost when implemented on distributed memory computers. This is especially true for harder problems such as indenite complex linear systems and systems of convection-diusion equations from three-dimensional compressible °ows. Both sequential and parallel results are reported