Are you running version 2.5 or later? The code became 2-3 times faster with the simple reorganization of the network node/link/data classes.
I’m using version 2.5.2
I’m not sure you can do anything significant.
I only have one layer
I have already applied with great success an external layout algorithm (www.graphviz.org) to improve the performances of the layout. It may not be as sophisticated as the GoLayoutLayeredDigraph (I don’t know if it handles ports, subgraphs, link strokes that go around nodes…), but it was much faster.
I don’t have specific amout of layers but in general my graphs are strongly connected.
it takes over an hour :(
Hmmm, I just tried using LayoutDemo on a graph with about 480 nodes – it took several seconds, definitely much less than a minute.