Wow, 8 hours. I thought my models that take weeks to run on overclocked CPUs were long. :-).
Anyway, to improve performance, consider using multiple computers if you're doing multiple simulations (that would mean more licenses = $$$); overclock your computer; reduce the amount of elements (or at least maintain the resolution closer to your important areas) whereby using triangle.dll for mesh generation is the best option usually; reduce the size of your domain (reduces the amount of elements); and take larger timesteps (pay attention to your Peclet number); avoid unsaturated problems if you can (these tend to take far longer than fully saturated problems); and potentially use the 'SAMG' solver for the solver type, if you have a multi-core processor and cooling it isn't a problem and you're running a steady state.
One important thing to note is that the more time you spend designing your supermesh, the better resolution you'll get around your areas of interest and the less resolution will be necessary in far-field areas. I typically try to minimize the amount of elements to the maximum while using Triangle.dll while minimizing delaunay triangle violations and the number obtuse triangles (which can typically be fixed after you generate your mesh if it isn't too refined around your areas of interest).
Adam
