I'm not sure what happened to the animation process. Suddenly my all animations are executing slowly. I've reset my Simulator, restarted my Mac, but doesn't help.
I'm not sure what I've done or its a system issue. Please check the below image. Every animation is executing slowly.
I'm using Xcode7.3.1, Simulator iOS 9.3. Its a simple pushViewController and nothing
This is just a minor problem. I think You have just checked the Slow Animation in simulator by mistake.
All you have to do is that Go to your simulator>Debug>Slow Animation
Uncheck Slow Animation
You have to check the Simulator First for Slow animation.
Debug-->slow animation OR cmd + T
You may have pressed Cmd + T. Press again Cmd + T to remove slow Animations in your Simulator.
来源：https://stackoverflow.com/questions/38321978/all-animation-are-executing-slowly