Android app runs fast on 5.1 but in previous version is very slow

Question

I have an app which runs fine on Android 5.1 but it takes ages to run on old android version, even though I configured the minimum target to 4.0.1 (API 15). The app is based on a mainactivity and switches among three fragments. For the fragments, I use support libraries, so that it can run on old version of android. Why could I be doing wrong? Some hint about having an for different android version using API 22?

Answer 1

If there isn't a problem in your code, check the old device ram and heap size also try selecting a good device for example galaxy nexus.

also some information for better performance for the emulator, here: Making the Android emulator run faster