Hi 3image - different lighting schemes do not change performance since lighting is completely done through environment mapping and the different lighting schemes just generate different map content. I guess if you disable specular highlights it will eliminate one additional texture lookup but that's going to be such minimal impact that I don't think you would be able to measure any difference.

If you have a heavy model the main thing to do to boost performance is to adjust the display mesh settings to make a coarser display mesh. To do that, go to Options > View > "Meshing parameters" and set "Mesh angle" to 25 or 30 degrees and uncheck "Add detail to inflections". That will make for a somewhat rougher and jaggedy looking shaded surface display but will also greatly reduce the number of triangles being used for surface shading. That also reduces memory consumption by a lot as well. The default value of 10 degrees is more targeted at making the display look nice for not too complex models.

The main other thing to do than that is to try and hide objects that are not pertinent to your current work. You can also just hide edges and curves for a pretty big impact because usually curve/edge drawing takes the most time. Also the hidden line display controlled by View > "Display hidden lines" requires a complete second pass for curve drawing and so disabling that can impact performance too.

- Michael