What is the best method to manage thousands entities with labels ?

I have to display 50000 entities with billboard and label... but it's not working:

viewer.entities.suspendEvents();

for (var i = 0; i < series.length; i++) {
    viewer.entities.add({
    position : Cesium.Cartesian3.fromDegrees(longitude, latitude),
    label : {
          text : series[i].id,
          font : '10px Helvetica',
          fillColor : Cesium.Color.SKYBLUE,
          outlineColor : Cesium.Color.BLACK,
          outlineWidth : 2,
          style : Cesium.LabelStyle.FILL_AND_OUTLINE,
          translucencyByDistance : new Cesium.NearFarScalar(1.5e5, 1.0, 1.5e7, 0.0)
            },
     billboard : {
    image : getIcon(series[i])
      }
     });
}

Removing the label it works with good performance.

Please can anyone help me ?

Thank you in advance.

Marco