I just started using telerik reporting and I'm wondering about this scenario. Basically, I created a business object based report with two levels of grouping. I'm accessing it through the web viewer and I'm sending it a list of Ienumerable<object>. There are about 24000 rows in the inenumerable. The report gets it, but it takes almost 2 minutes to render (it takes 2 seconds to get the data). The report winds up being 1900 pages. I'm wondering, are the pages loaded on demand? Is there some kind of way to speed this up by loading a page at a time?