Xcode Simulator device slow and jerky

Goodmorning everyone, I created a scene in Unity with inside animation and created the build iPad. I tried to test it by loading the solution on Xcode and using the simulator for iPad2 ... smoothly .. just like the game of Unity. But if I try to change device simulator Xcode, iPad Retina, iPad Air and iPad Air 2, the animation is slow and jerky ... I was wondering if anyone has encountered the same problem and how it has solved. thank you.