Xcode Simulator animations extremely slow when played in editor

XCODE 9 BUG. This is officially confirmed to be an issue with Xcode 9.0 and its iOS 11 simulator — it affects any OpenGL-using application.

See: https://github.com/mapbox/mapbox-gl-native/issues/9959

Also: https://twitter.com/xenadu02/status/911463433521860609

:( Hope this helps.


Currently only iOS11 simulator is slow.

You can download additional iOS10 simulator which works perfectly.

Choose Xcode -> Product -> Destination -> Download simulators... Then select any iOS10 simulator from the list (e.g. 10.3.1).

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After that you will choose iOS version for most devices:

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In Simulator menu, go to Debug > Slow Animations , and uncheck this option or simply do:

+ T


If you press command+T it triggers the 'Slow animations' feature. I didn't noticed this setting until now. Doh!