The arithmetic mean preconditioner for multivector computers

In this paper we consider the arithmetic mean preconditioner for the conjugate gradient method. This preconditioner is designed to be implemented on a multiprocessor system that can execute concurrently different tasks on vector processors.Some spectral bounds for the preconditioner have been obtained. A comparison between this preconditioner and the SSOR preconditioner has been carried out on different test-matrices. Also the m-step preconditioners generated by the arithmetic mean preconditioner and by the SSOR preconditioner have been compared.