How can I optimise Invalidate() calls with MSChart?

I have 3 different graph displays which make use of the MSChart library for C#. I am updating the graphs with data as it becomes available in real time. The function which updates the display runs approximately every 40ms, and goes something like this:

private void UpdateDisplay()
{
    // Process data for graph 1
    // (Graph 1 has 2 Line graphs, and 1 Candlestick)

    // Get the series
    Charting.Series lineGraph1 = graph1.Series[0];

    // ....process s开发者_如何学编程ome data and generate new data....

    // Update the data
    for (int i = 0; i < displayedSamples; i++)
    {
        lineGraph1.Points[i].YValues[0] = newData[i];
        // ....update other series' data....
    }       

    // Redraw the graph
    graph_1.Invalidate();
    graph_1.Update();

    // Process data for graph 2
    // (Graph 2 has 1 bar graph)
    // ...
    graph_2.Invalidate();
    graph_2.Update();

    // Process data for graph 3 and update points
    // (Graph 3 has 2 column graphs)
    // ...
    graph_3.Invalidate();
    graph_3.Update();
}

Running the application causes the CPU usage for the app to skyrocket. If I remove only the "Invalidate()" calls, then the CPU usage for the application is close to 0%.

The set of points in the series stays consistent. All points are added when the series are generated, and then the values of the points are just updated.

I have tried to improve performance by only invalidating the points in the displayed series (i.e. graph_3.Series[0].Points.Invalidate()), but this has had no noticeable effect.

What are my options to improve the performance?