Mysterious performance drop still remains!?

Hey guys,

I posted a question about a mysterious performance drop a few months ago. It’s about my laptop performing quiet well up until a certain point. After a few minutes of intensive work (gaming etc.) the performance drops massively. Back then some people said it was the RAM. I installed 8192 MB of DDR3 RAM running at 1333 MHz. Did not solve the problem. I got tips about my GPU overheating, I installed a Trust Cyclone Cooling pad. Which also did not do much about the problem, the temperatures did lower. What could this also be? Can it be driver related?