[jongthechemist]

Hi guys. I remember that Microsoft said that app performance should be better in WP8.1 but the app package has to be retargeted to WP8.1. As we can see the file explorer and calendar app are fast and fluid. I assume that they are not integrated part of the OS since they have splash screen.

My first question is, has any developer tried to compare their app on WP8 and repackaged for WP8.1? If you do, does it really gives the app a better performance?

Another thing that I noticed is in the podcast app, the panorama header's animation is not as smooth as in WP8. But it behaves differently in the store/xbox music apps. Someone said the xbox music app is a WP8 app because the background audio API for WP8.1 is not ready. This confuses me because the podcast app has to be a WP8.1 app because of the weird panorama animation but it also has to use the backgroud audio API. The app's performance is not great compared to the files app. Why is it like that? Any guess which OS is it targeted to?

Last but not least, I read a blog comparing Swift and Objective-C for iOS. Swift, if optimized is a lot faster than Obj-C. For Windows Phone, there's Silverlight 8.1, WinRT C#, C++ and also WinJS. I can't find anywhere comparing the performances of these different languages. Have you find any or have you done it yourself? Which one is the best in terms of performance?

Sorry if I'm not clear with my intention. There are now a lot of ways to develop for WP and I'm searching to find the best way to offer WP users the best experience on Windows Phone. I can't brag about how fast it is anymore since Android has caught up (for high end devices at least). I'm guessing if every app are optimised like these two apps, WP users can be proud again of their fast and fluid OS.

[luke_f]

The fastest language to develop for WP is C++. The core of windows is written in native code (c/c++). If you use a different language, then each time that your code calls framework code, or the other way round (data binding, events), there is a tansition between native and C# / javascript, and back again at the end of the call. This makes apps using C# and javascript slower, compared to C++. Additionally, C# and JS have a "garbage collector" which eats about 10-15% of your performance. In C++ you do the work of the garbage collector yourself, which is more efficient but also more work and more error prone.

So if performance is your main decision point, you should go for C++. However, C++ is rather complicated and difficult to use, if you are not already used to it. I am developing in C# because it allows me to be a lot more productive, compared to C++... For C# vs JS, I think they are more or less on the same level. Maybe C# is a tad faster, but not much. So there it is a matter of taste. If you are already accustomed to one of the languages, it's probably best to stick with it. Personally I prefer C# especially because async programming is easier vompared to JS - and with WP8 and higher you are forced to use async stuff a lot.

[Vaipa]

If you're building a high performance game you should go for C++ as it's the fastest choice. Also, coincidentally, windows phone is the only platform that allows you to create a pure C++ app. On all other OSes you have to wrap the app into something, such as Obj-C on iOS or Java on Android which make things slower.
The only big problem with C++ on Windows Phone is that not all APIs are available for it. So if you plan to use something like live tiles , or phone call interaction.. you're forced to use C#.