FPS drop suddenly on R7 M360

Hello,

 

So I'm using Lenovo Ideapad 500 with AMD Radon R7 M360, 16 GB RAM and Windows 10.

 

I play Freestyle2 and Overwatch

My FPS usually stay at 50-62 FPS,

Untill last nite (6 May 2017) It was completely fine, but today ( 7 May 2017 suddenly my laptop always got FPS Drop every 2-3 minutes for about 10 secs and I'ts so frustating.