J Supercomput (2008) 44: 237–256 DOI 10.1007/s11227-007-0157-x A multilevel parallel algorithm to solve symmetric Toeplitz linear systems Miguel O. Bernabeu · Pedro Alonso · Antonio M. Vidal Published online: 14 December 2007 © Springer Science+Business Media, LLC 2007 Abstract This paper presents a parallel algorithm to solve a structured linear system with a symmetric-Toeplitz matrix. Our main result concerns the use of a combination of shared and distributed memory programming tools to obtain a multilevel algo- rithm that exploits the actual different hierarchical levels of memory and computa- tional units present in parallel architectures. This gives, as a result, a so-called paral- lel hybrid algorithm that is able to exploit each of these different configurations. Our approach has been done not only by means of combining standard implementation tools like OpenMP and MPI, but performing the appropriate mathematical derivation that allows this derivation. The experimental results over different representations of available parallel hardware configurations show the usefulness of our proposal. Keywords Toeplitz matrix · Cauchy-like matrix · Rank displacement · Multilevel parallel programming · MPI · OpenMP 1 Introduction In this paper, we present a parallel algorithm for the solution of the linear system Tx = b, (1) where T R n×n is a symmetric Toeplitz matrix T = (t ij ) n1 i,j =0 = (t |i j | ) n1 i,j =0 and b,x R n are the independent and the solution vectors, respectively. M.O. Bernabeu () · P. Alonso · A.M. Vidal Departament de Sistemes Informàtics i Computació, Universitat Politècnica de València, 46022 Valencia, Spain e-mail: mbernabeu@dsic.upv.es P. Alonso e-mail: palonso@dsic.upv.es A.M. Vidal e-mail: avidal@dsic.upv.es