heating of nvidia gforce 8400gs game slows down in between while playing

can someone help me about how to solve the problem of this graphics card of nvidia (8400gs) due to it my games slow in betweeen i want o get out of this problem so i would be thankful to anyone helping me about this problem.

Install a freeware utility called SpeedFan and look at the graphs of CPU and GPU temps over time while you’re playing.

The GPU would usually throttle down at 105 deg celsius (as far as I am aware).

Another utility called gpu-z may be able to display GPU frequencies in a plot, so you can see if it gets clocked down.

EDIT: the CUDA programming forum is not really the right place to ask this hardware question.