Thank you for writing.
You can perform some sql grouping operation in your data before attaching it to RadChartView. Another solution is to aggregate the data - that is, reduce it to a smaller number of points by 'combining' values by taking their averages.
For example you can have 50,000 points. If you average every 10 values, the number of points is reduced to 5000. That is still too many, so you could average, say, in blocks of 100 or even 250. Alternatively, aggregate a previous aggregate - with, say, 10 values in each takes you down from 50,000 to 5000 to 500.
I hope this information is useful. Let me know if you need further assistance.
All the best,
the Telerik team