Small FPS with 5000+ entities

CesiumJS
1

Hello! When I try to add 500 entities which has plane in it, while I customize dimensions property via CallbackProperty for smoothness of scaling, the FPS is very low. What could be the solution? My code:

const viewer = new Cesium.Viewer("cesiumContainer");

const newDimensions = new Cesium.Cartesian2(156000.0, 156100.0);
for (let i = 0; i < 500; i++) {
  const latitude = (Math.random() * 180) - 90;
  const longitude = (Math.random() * 360) - 180;
  const height = Math.random() * 1000000;
viewer.entities.add({
  name: `Entity ${i}`,
  position: Cesium.Cartesian3.fromDegrees(longitude, latitude, height),
  plane: {
    plane: new Cesium.Plane(Cesium.Cartesian3.UNIT_Z, 0.0),
    material: new Cesium.Color(1.0, 1.0, 1.0, 0.9),
    dimensions: new Cesium.CallbackProperty(() => {
      return newDimensions;
    }, false)
  }
});
}
viewer.scene.preRender.addEventListener(function () {
  let cameraHeight = viewer.scene.camera.positionCartographic.height;
  var newSize = 30000.0 * (cameraHeight / 2000000);
    newSize = Math.max(newSize, 100.0);
    let minHeight = 1000000;
    let maxHeight = 20000000;
      if (cameraHeight > minHeight && cameraHeight < maxHeight) {
      newDimensions.x = newSize;
 newDimensions.y = newSize;
    }

});