Heavy lag after update

After updating to 1.0.0.0 from 0.17.0.2 the frame rate dropped very highly. Before I used to get 58-59 fps, now I am only getting 30 fps max. Sometimes it is dropping to 6 fps. And I have a very decent device.
I am using a OnePlus X with 3 GB RAM and 2.3 GHz snapdragon 801 processor and afternoon 330 gpu