- Main Matrix System (Asymmetric Method):
- Asymmetric - must use an asymmetric solver like GMRES, BCGS or TFQMR
- Size is
3
*n*_{c}+*n*_{b}/2 squared - Maximum of 7 non-zero elements per row

- Main Matrix System (Support Operator Method):
- Symmetric - can use CG to solve
- Size is
3
*n*_{c}+*n*_{b}/2 squared - Maximum of 9 non-zero elements per row

- Preconditioner for Krylov Space methods is a
Low-Order Matrix System:
- Assume orthogonal: drop out minor directions in flux terms
- Symmetric - can use standard CG solver
- Size is
*n*_{c}squared - Maximum of 5 non-zero elements per row

Michael L. Hall