Phone [Q] [MTK6572][4.2.2] Why not smooth?

I bought a Navon MIZU M400 phone yesterday.
Default, it have a 4.2.2 Android. It's okay, but it's not smooth!!!!
I think a Dual-Core GPU Mali™400 GPU is not give a non-smoothable system for me.

I read a LOT of forum themes for this. I read about "Rotate my phone, press the recentry apps, etc etc..." but it's not working.
I try everything in the development opportunities menu.

I dont wanna root, because i bought yesterday..

With LOT OF THANKS, SnikerFreak