Character Controller collision speed

I have a bunch of blocks which I want interact with when they collider with my Character Controller. Here is the code I am using:

function OnControllerColliderHit(hit : ControllerColliderHit) { renderer.material.color = Color.blue;

 if(hit.gameObject.tag == "Block")
 {
      var block;
      block = hit.gameObject.GetComponent("Block");
      block.collide();
 }

It works, but it's quite slow in computing the collision, there is about a half second delay before the block's collide() method is called.

Is there a faster way to check for collisions with rigidbodies and a character controller?