low gpu clock speed

Here's my system, for starters— LAPTOP Dell Inspiron 5737 core I7-4500U 1.8 GHz Radeon HD8870M dGPU (detected by Windows as R9 M200X) Intel HD4400 integrated GPU 8GB DDR3 The problem started a few months ago, whereby, at some points when playing, the screen would start to stutter with lower FPS...