The advent of vector and massively parallel computers offers researchers the possibility of enormous gains in execution time for scientific and engineering programs. From the numerical point of view, such programs are frequently based on the inversion of sparse, diagonally banded matrices. Conventional scalar solvers often perform poorly on vector machines due to short effective vector lengths, and thus appropriate methods must be chosen for use with vector machines. In this paper a number of commonly used solvers are tested for the Navier-Stokes equations, in both scalar and vector form, on two vector architecture machines. A new method is presented which performs well in both vector and scalar form on a range of vector architectures.