The Mixed Finite Element Multigrid Method for Stokes Equations

Table 6

Number of iterations and CPU time of iterations for multigrid (-cycle) with different smoothers and using one -cycle multigrid preconditioner approximation (for both and ) at different levels of refinement, tolerance = .

Levels	MG--cycle()
	DGS	IUzawa	Braess-Sarazin	PMINRES
	Iter(cpu time (sec))	Iter(cpu time (sec))	Iter(cpu time (sec))	Iter(cpu time (sec))
	14 ()	10 ()	6 ()	13 ()
	15 ()	10 ()	7 ()	14 ()
	16 ()	11 ()	8 ()	14 ()
	16 ()	11 ()	8 ()	14 ()