I haven't used the application (can't on Linux), but if the graph doesn't require user interactivity, using Cairo or some other software renderer (e.g. http://w

I haven't used the application (can't on Linux), but if the graph doesn't require user interactivity, using Cairo or some other software renderer (e.g. http://www.antigrain.com/ http://www.antigrain.com/) to just render the graph into a bitmap, would do the job faster and with less resource usage. Adding user interactivity on top of that shouldn't be a lot of work either.