I've been looking into Silverlight charting controls to display a large number of samples, (~10,000 data points in five separate series - ~50k points all up). I have found the existing options produced by Dundas, Visifire, Microsoft etc to be extremely poor performers when displaying more than a few hundred data points. I believe the performance issues with existing chart controls is caused by the heavy use of vector graphics. Ergo one solution would be a client-side chart control that uses the WritableBitmap class to generate a raster chart. Before I fall too far down the wheel re-invention rabbit hole - has anyone found a third party or OSS control that will manage large numbers of data points on a sparkline?