In this paper we demonstrate the parallelism of the spectral division using
the matrix sign function for the generalized nonsymmetric eigenproblem. We
employ the so-called generalized Newton iterative scheme in order to compu
te the sign function of the matrix pair. A recent study showed a considerab
le reduction (by 75%) in the computational cost of this iteration, making t
his approach competitive when compared to the traditional QZ algorithm.
The experimental results on an IBM SP3 multicomputer report the parallel pe
rformance (efficiency around 60-80%) and scalability of this approach.