Maya internally converts NURBS objects to polygons before it animates the simulation. The Tessellation Factor sets the number of polygons created during the conversion. Lower numbers create coarser geometry and lessen animation accuracy (which means more fluid will appear to pass through the geometry), but increase the playback speed and processing time.

The default Tessellation Factor is 200. Try doubling the value as many times as necessary to get the desired smoothness. (Select the geometry and click the geoConnector tab in the Attribute Editor.)