Fps sag

Laptop
i3 2310M
4Gb ram
gt 525M
In any game, no matter what year of release, FPS drops occur, be it tanks or dota or gta san andreas.
Every 5 seconds, fps drops to 20, or even lower then sharply to 60 or higher, does not depend on the terrain, even if you leave the camera in one place, first it will be 20 fps, then 60, then again 20, and so on until you turn off the game.
Windu changed, updated firewood, cleaned all the registry itself, the laptop itself, the rug next to it), did anything, but there is always a FPS sag in any game even with a resolution of 800x600,

I watched the video card in the game using MSI Afterburner GPU load from 20% to 60 % and jumps in this value above can not, 60 degrees ceiling for vidyuhi above does not heat up the percentage either. the laptop itself is cold.

Help solve this problem, it's impossible to play, maybe there is a function that prevents the video from working in 100%? overheating blocking xs ,, ????. help