For ILUT, the relative memory requirement is equal to
3 shows the performance of SCPRE and XPABLO for block Gauss-Seidel iterations and their comparison with ILUT.
Note that we used the BTF forms of the reducible matrices for both the XPABLO and ILUT preconditioners.
4 shows the results of additional experiments conducted to further compare the memory usage of SCPRE and ILUT preconditioners.
ILUT is not included here since it does not explicitly give a block diagonal structure.
Although our preconditioner SCPRE is outperformed by ILUT for electromagnetics matrices, we obtain promising results for many device and circuit simulation matrices, and we suggest using it with these types of problems.