Work on generalizing the deflated, restarted GMRES algorithm, useful in lattice studies using stochastic noise methods, is reported. We first show how the multi-mass extension of deflated GMRES can be implemented. We then give a deflated GMRES method that can be used on multiple right-hand sides of Ax = b in an efficient manner. We also discuss and give numerical results on the possibilty of co...

The global FOM and GMRES are among the effective algorithms to solve linear system of equations with multiple right-hand sides. In this paper, we study these algorithms in the case that the coefficient matrix is symmetric and extract two CGtype algorithms for solving symmetric linear systems of equations with multiple right– hand sides. Then, we compare the numerical performance of the new algo...

Using a recently proposed communication optimal variant of TSQR, weak scalability of the least squares solver (LS) with multiple right hand sides is studied. The communication for TSQR based LS solver for multiple right hand sides remains optimal in the sense that no additional messages are necessary compared to TSQR. However, LS has additional communication volume and flops compared to that fo...