As of the 1st of August, 2014, Xamarin issued the version 1.2.2 of the platform (version 1.2.1 proved really buggy. Luckily, the Xamarin guys patched it well).
I can now test how Xamarin Forms performs (in terms of speed) compared to a “classic” Xamarin iOS development.
I did a very similar test to the one we did on Android.
It is, in “Release” mode:
1. I create a scrollview for 50 times.
2. To every scrollview I add: 20 labels, 20 textfields with a placeholder, 20 buttons with an event handler.
3. all the labels, textfields and placeholders are removed from the scrollview and destroyed (except for the 100th iteration)
4. the scroll is removed from the root view (except for the 50th iteration)
Xamarin.iOS “Classic” (with iOS designer on visual studio, “release” configuration):
average of 3710 milliseconds on the iPhone 5 64 bit “simulator”
average of 14050 millseconds on the iPhone 5 “classic” device
Xamarin.Forms “Classic” (with iOS designer on visual studio):
average of 141 milliseconds on the iPhone 5 64 bit “simulator”
average of 609 millseconds on the iPhone 5 “classic” device
So, in terms of how fast it is, on iOS Xamarin Forms beats Xamarin “classic” as it happens with Android, at least when it comes to standard UI buttons, labels and textfields.
This is the code: