GMRES Method and its Uses

What is GMRES method? When can it be used?

GMRES is a new stabilization method which means Generalized Minimal Residual Method.
It is used for improving convergence of the linear solver and providing stability for the algebraic multigrid (AMG) solver.

GMRES is recommended when you cannot reach convergence with the bi-conjugate gradient stabilized method (BCGSTAB)

For more information, please check the user guide.