Stability and performance analysis of a block elimination solver for bordered linear systems

A new block elimination method for bordered systems is proposed and its num erical properties are analysed. In the case where the leading principal blo ck is ill-conditioned or singular and the method becomes unstable a perturb ation approach is used to enhance the stability. Results of experiments per formed on the SGI Power Challenge 8000 and on the Gray J-9x illustrate the performance of the new algorithm and compare it with the current best appro ach. It is shown that the new method works faster while preserving stabilit y.