samsung note 4 quadcore: 2cores turned off

[5hah3]

when i try to play tekken 6 on galaxy note 4 n910v, the games is really slow, like 25-30 fps. when i switch from ppsspp to check cpuz , my 2 cores (core 2 and 3 ) vary from inactive to active , and not stay active constantly. when i switch from cpuz to ppsspp, the game speeds up to 45-50 fps, for 4 seconds, then steadily goes back to 25-30 fps. the mobile is does not feel hot, so no thermal throttling i think. the softwere is 6.0.1 android version. please help me to run this game smoothly. also, the gpu load on mobile is always 0%, when i check from cpuz, no matter if the game is running or not.