The computation of the physics simulation (applying forces between nodes, ending once it finds a local minimum) is an intensive process. You could do it all at

The computation of the physics simulation (applying forces between nodes, ending once it finds a local minimum) is an intensive process. You could do it all at once but it would probably hang your page for a meaningful time. You could also reduce the framerate or only show the results at the first an final frames, but those also have user interface implications.