Report Viewer Load Speed

I have created an SQL query containing several thousand lines:
Dim ps As New PrinterSetup
Dim rpt as Report
Dim rs as recordSet

  If rpt.Run( rs, ps ) Then
    If rpt.Document <> Nil Then
      winInventory.ReportViewer1.SetDocument( rpt.Document )
      winInventory.ReportViewer1.Canvas1.Refresh( False )
     .....

The issue is that the Report viewer takes several minutes to display the data. However I can export that data to a csv file in seconds and can export to fpdf in 2 -3 seconds. I am trying to get some guidance on why this is so slow. Small SQL queries are very fast.
Thx

Every page of the report is being created as a graphic file and so with several thousand lines I would image that it is generating quite a few pages, or in this case graphic files that are representing those pages.