The number of appointments and resources slows down the rendering and overall performance
considerably which has to be expected. I am not sure whether you are
using the latest version of RadControls. In the previous releases the
images to support the appointment rounded corners (and the
predefined resources) were quite large. For example in the Q1 2010
release, the appointment sprite
itself is taking 25MB memory when loaded. Add 5 resources to the fray
and you have 150MB memory down with a single blow.
As far as I know there isn't anything particular that you can do with
RadScheduler. Still you can review the optimization techniques as shown
demo. Another suggestion is Client side binding using web services can
give you excellent performance in most common cases as shown here.
Apart from this some general performance tips you can incorporate such
as using RadScriptManager and RadStyleSheetManager to optimize output as
well as page load time as described here. Also you can read more about the general performance tips from here Link1, Link2.