Slow delay/latency running project on device in Swift

Question

I have a swift project on Xcode 9.2, running on iPhone 5s as a test device. The project, using GameplayKit and SpriteKit, is small but still when I run the project on the device it have a really slow delay (about 5 - 10 seconds), and in general the animation even that there is no too much, is very slow. Objective-C works extra fast with heavier project on the same device. Any Idea how to improve the performance?

Answer 1

I manage to find solution :) In the Project Target's build settings, uneder LLVM 9.0 Code Generation -> optimization Level: I've changed the debug setting from 'none' to 'fastest,smallest' and the project works as expected, without any latency!

Here is a screenshot of the settings screen: