RadChart will have problems with thousands of items on screen. While the product was designed to be easily customizable and feature rich it does not cope well with extremely busy charts.The control is targeted for casual situations which do not require a high performance solution. There is a trade off to make between high customization and high performance and we've gone the rich features path as it is what most of our customers are interested in.
You may consider applying some sort of sampling on the data:
is added to i
in each loop, that is -- getting the first 50 items and calculating their average value, then the next 50 items and so on. Please accept our apologies for not being able to meet your requirements.
the Telerik team