How to display numerous interpolated entities ?

Hello,

Could someone tell me what is the best way to display a lot of entities which are following a path ?

If I run the Interpolation Sandcastle with the viewer.scene.debugShowFramesPerSecond in my browser (Chrome), it displays around 60 FPS.
But, my problem is if I modify this sample, creating about 100 entities in a loop at random positions, my FPS is falling to 8.

My final aim is to display about 1000 moving entities...

Thanks.