I made it - and quickly rewrote it to use canvas. With many points the performance of SVG is simply not acceptable. On the other hand, for canvas they are just

I made it - and quickly rewrote it to use canvas. With many points the performance of SVG is simply not acceptable. On the other hand, for canvas they are just pixels (once they are drawn) - no difference in performance if they are white or green. Note that I love SVG and still use it for the axes and the layers above the chart, but it has too much overhead to be used for drawing the chart values.