1. Simplify the geometry by removing unnecessary elements from consideration.  See this article for possible techniques.  Curved surfaces slow ElumTools down the most, so try to remove those when possible.
  2. Validate reflectance values in Material Mapping. See online help  and  YouTube video.  Surfaces with unrealistically high reflectance values (typically >0.8) can slow down the calculation substantially. 
  3. Modify the ElumTools settings (below). Access the ElumTools Settings button from the ElumTools toolbar.
    • Note: ALL of these suggestions come at the expense of accuracy. Therefore these suggestions should be used for design iterations only. Final submittals should always be prepared using the default settings or better. 

    • Lower the stopping criterion either manually or by adjusting the Accuracy Setting.
    • Disable adaptive subdivision. Adaptive subdivision is a process that intelligently divides surfaces to apply a finer mesh in areas of high luminance gradients. This improves the rendering quality and calculation accuracy in areas where there are shadows, but does slow things down.

    • You can skip to the end of a calculation using the button shown below. This is effectively the same thing as lowering the stopping criterion.