为什么MapPoint.Route.Calculate（）比在应用程序本身中计算慢得多？

class CalculateTime : IDisposable
{

    MapPoint.Application app;
    MapPoint.Map map;
    MapPoint.Route route;

    public CalculateTime()
    {
        app = (MapPoint.Application)Activator.CreateInstance(Type.GetTypeFromProgID("mappoint.application"));
        map = app.ActiveMap;
        route = map.ActiveRoute;
    }

    public class Place
    {
        public string City { get; set; }
        public string Street { get; set; }
        public string Postal { get; set; }

        public Place(string City = "", string Street = "", string Postal = "")
        {
            this.City = City;
            this.Street = Street;
            this.Postal = Postal;
        }
    }

    public class Place
    {
        public string City { get; set; }
        public string Street { get; set; }
        public string Postal { get; set; }

        public Place(string City = "", string Street = "", string Postal = "")
        {
            this.City = City;
            this.Street = Street;
            this.Postal = Postal;
        }
    }

    public TimeSpan Calculate(Place From, Place To)
    {
        Stopwatch sw = new Stopwatch();


        MapPoint.FindResults frFromCollection = map.FindAddressResults(City: From.City, Street: From.Street, PostalCode: From.Postal);
        MapPoint.FindResults frToCollection = map.FindAddressResults(City: To.City, Street: To.Street, PostalCode: To.Postal);

        object frFrom = frFromCollection[1];
        object frTo = frToCollection[1];

        route.Waypoints.Add(frFrom);
        route.Waypoints.Add(frTo);

        sw.Start();
        route.Calculate();

        TimeSpan time = new TimeSpan(0, (int)(route.DrivingTime * 24 * 60), 0);
        route.Clear();

        sw.Stop();

        Marshal.ReleaseComObject(frFromCollection);
        Marshal.ReleaseComObject(frToCollection);
        Marshal.ReleaseComObject(frFrom);
        Marshal.ReleaseComObject(frTo);

        MessageBox.Show(sw.Elapsed.Seconds + "." + sw.ElapsedMilliseconds);
        return time;
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    ~CalculateTime()
    {
        Dispose(false);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (disposing)
        {
            map.Saved = true;
            Marshal.ReleaseComObject(route);
            Marshal.ReleaseComObject(map);

            app.Quit();
            Marshal.ReleaseComObject(app);
        }
    }
}

MapPoint.Route.Calculate()

Calculate