For elliptic PDEs (Poisson-type), the multigrid method is very sufficient, but how about time-dependent problems (i.e parabolic or hyperbolic PDEs)? Is it efficient to solve such problems using a multigrid method?
Somewhere I read that for very small time steps a classical iterative method (i.e GS) may be a better option than multigrid and for larger time steps multigrid is efficient. Is this statement correct?