Hi,
As per my understanding there is no definitive answer as to when OpenGL will perform better than Painters or vice versa. Generally Painters does well with simple plots and 2-D graphics. With hardware acceleration, OpenGL generally performs better than painters for 3-D plots.
I would recommend setting the figure "RendererMode" and the "DefaultFigureRendererMode" to "Auto", so that even though you have established the default figure renderer, MATLAB can still switch the renderer at run time based on its own inbuilt logic.
Further, some generic suggestions that might be of help - I recommend reading this documentation page on Graphics Performance, some of the concepts here might be applicable to your use case. Finally, please verify that your graphics card drivers are up to date.
