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If used with a Coarse Solver, select a Termination technique. These are described for the SCGS attribute under Settings When Used With a Coarse Solver.
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If a Coarse Solver is not used, enter the Number of iterations to specify a fixed number of iterations to perform when this attribute is used as a preconditioner or smoother (default: 2).
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Select Direct (the default) to use a direct solver.
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Select Direct, stored factorization to store the factorization. Storing the factorization makes the solver faster because the factorization is then not performed every update, but the storage uses more memory. If two Vanka smoothers are used as a presmoother and postsmoother of a Multigrid solver, with similar enough settings, they share the same stored factorization, which means that they only use half the memory.
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Select Iterative, GMRES to use the iterative method GMRES.
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If you use the Vanka algorithm as preconditioner or as smoother to a multigrid preconditioner when GMRES, Conjugate gradients, BiCGStab, or TFQMR is used as the linear system solver, use the Direct or Direct, stored factorization option in the Block solver list to get a stationary preconditioner.
The Iterative, GMRES option can be useful if you use the FGMRES method as linear system solver because it can handle preconditioners that are not stationary. The Iterative, GMRES option can also be useful if you use the Vanka algorithm as a smoother to a multigrid solver because GMRES can be a bit faster than the direct solver.
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