VECTORIZATION OF SOME BLOCK PRECONDITIONED CONJUGATE-GRADIENT METHODS

The block preconditioned conjugate gradient methods are very effective to solve the linear systems arising from the discretization of elliptic PDE. Nevertheless, the solution of the linear system Ms = r, to get the preconditioned residual, is a 'bottleneck', on vector processors. In this paper, we show how to modify the algorithm, in order to get better performances, on such computers. Numerical tests carried out on a CRAY X-MP/48 are presented, in order to give numerical evidence. © 1990.