Performance hit with touches

Unity Engine
,
1

Two performance questions:

  1. I’ve got a scene that exclusively contains sprites (via SM2) and planes with rotating/panning textures. The setup runs smoothly at about 29 fps on 3g. Once I put my finger on the screen, the framerate drops down to 22 fps. All input scripts and game logic are disabled, so I know it’s not an expensive script taking the extra time. There are no OnGUI calls or colliders on screen. Is it common for input touches to have such a large impact on performance?

  2. I currently have roughly 30 sprites batched that need to slowly rotate with a unique speed. At the moment I have them all running a script with a defined rotation speed and a single line Update that instructs the individual object to rotate. Is there a more performance friendly way to handle continuous rotation of many objects at once?

public float rotSpeed;

void Update(){
     transform.Rotate(rotSpeed * Time.deltaTime, 0f, 0f);
}
2

This might not be extremely helpful, but whenever I see performance problems with touch operations, I first check that my script execution is set to Fast but no Exceptions. Setting it to slow is well… slow, dead slow when dealing with touch systems.

As for the rotate script, it might help to cache the transforms. In JS it would be something like:

Should be similar in c#;