I'm using a NVIDIA GeForce 9400 GT card and I noticed the last few days that my computer would become laggy after some time. I narrowed it down and found it was the GPU temp. It reached over 90C and then one time it shut off (screen went blank).
Now I put a little separate fan right in rear of the computer to try and keep the graphics card cool. It stays at around 70-75C now with my manual fan on. If I turn it off, the GPU temp starts to climb again. Fan speed indicates that its running at 75% speed. I did a visual test too and see the fan spinning.
So I'm not sure why the GPU temp going over and overheating even though the fan seems to be working? Anyone have any suggestions what I can do next?