How to improve the speed of the map

VCL TMS VCL WebGMaps
1

I have on the map 700 markers and it works too slow.


Now I hide markers which do not fall into the visible area but it does not help.
procedure TfrmCity.OnMapZoomChange (Sender: TObject; NewLevel: Integer);
begin
    frmCity.DBMap1.GetMapBounds;
end;

procedure MapsOnBoundsRetrieved(Sender: TObject; Bounds: TBounds);
var
    i, c: integer;
begin
    c := frmCity.DBMap1.Markers.Count-1;
    for i := 0 to c do
    begin
        if (frmCity.DBMap1.Markers.Longitude > Bounds.SouthWest.Longitude) and
           (frmCity.DBMap1.Markers.Longitude < Bounds.NorthEast.Longitude) and
           (frmCity.DBMap1.Markers.Latitude > Bounds.SouthWest.Latitude) and
           (frmCity.DBMap1.Markers.Latitude < Bounds.NorthEast.Latitude)
        then
        frmCity.DBMap1.Markers.Visible := True else frmCity.DBMap1.Markers.Visible := False;
    end;
end;


Can you suggest something else to improve the speed?


p.s.
Google My Maps with 700 markers works fast
https://www.google.com/maps/d/viewer?ll=43.21050113181595%2C27.901537067015624&z=13&mid=1O4k4hgfJcpwaFCt49rlzMAWuVWNQutWT
2

Hi,


I would suggest to remove all markers with "DeleteAllMapMarker" and then only add the markers that should be displayed with "CreateMapMarker".