Overheating graphics card on a laptop?

Question

Video cards

In general, the essence is this.
I bought a laptop from my hands, without immediately checking it in games, I cleaned it of dust, changed the thermal paste, demolished Windows, returned the BIOS to the initial settings.
I launch various games and observe very low FPS.
In CS:GO - 120 fps is stable at maximum speed, but the whole screen is in artifacts.
In Dota2 - everything is in order (30-40 fps on ultra)
In Velmak 3 - 15 fps on any settings. (even at 640x480)
Sinned on the driver. Reinstalled - same thing.
I ran a video card test and noticed that under load it heats up to 93 degrees in a few seconds, and then throttling works (presumably), and after the load stops it also quickly cools down to 40 degrees (literally in 3-4 seconds.)
The cooler is working, the CPU does not heat up, although it is cooled together with the video card (with one cooler)
What should I do?
i7 - 3630QM 2.4GHz
GT640M 2GB
8GB RAM
Windows 7 x64

Answer 1

Does your laptop make a lot of noise when under load?

Answer 2

Where did you change the thermal paste? Only on the processor or even on the video card?

Answer 3

The cooling system itself is faulty, a rare problem, you need to buy a new one, and you can leave the old cooler.
It happened with a laptop, only the processor was heated at 100 degrees, and the video card was 60 degrees, the cooling system tube that came from the processor was faulty. Maybe someone will come in handy.