title: Ios UILabel update performance
body: <p>in my application i have an UILabel showing a time updated every second.
  I have also draggable objects in the screen.
  When I hide the label or i stop the timer everything is perfect but when i start the timer the animation performance of dragging objects go down.
  I put the UILabel updating in a separate thread but no luck.
  I need help friends :)</p>