Google Map Control - Waypoints Route

I am working on a asp.net c# application by using google map control. I am displaying 80+ markers on the lat/ long receceiving from database. Now I want to display a route covering all the markers. I have written a code for route generation but its showing route on very limited markers.

I have search on google and some where its mentioned that there is a restriction of 10 location route generation, if it is then how could I accomplish this task?

GoogleMap1.Directions.Add(new GoogleDirections()
                {
                    Origin = new Location(preLat, preLong),
                    Destination = new Location(Convert.ToDouble(geo.Lat.ToString()), Convert.ToDouble(geo.Long.ToString())),
                    Draggable = false,
                    SuppressMarkers = true,
                    PolylineOptions = { StrokeColor = "red", StrokeWeight = 3 },

                });