Nvidia 820m reduces clock speeds when running 3D application.

[SyMix_KD]

Greetings,
So I have a Geforce 820m:

On idle, it runs at 720mhz (I guess GPU boost applies here since default is 625mhz)
But when I try to run a 3d application like CS:GO or FurMark, it reduces clock speeds to 270mhz!
Wich is just INSANE, I go from 120fps to 40fps in CS:GO.

As you can see is not a problem with temperatures. My core i5 also does not go above 75c
This also happens with the Intel HD Graphics 4000 but instead the Intel HD Graphics 4000 always stays on 320Mhz on idle and full load.

The laptop is on max performance setting and in Nvidia's control panel I have it to prefer maxium performance.
I'm running windows 10 8gb ram with core i5.

I really need help fixing this problem.

I already tried:
-Doing a full re-install of nvidia drivers.
-Installing MSI Afterburner and overclock it.
-Removing battery from laptop

If you have any questions please dont hesitate.
Thanks!

EDIT:
This is crazy!
This is what hapenned when I turned off my external laptop cooling pad:

So i'm guessing the set temperature for thermal throttling is 72c? Because everytime it goes to 73c it's when the clock reduces speed.
I don't even know, just tell me what you guys think I should do.
Again, thanks!

 

[Shaun o]

I don`t know how old the laptop is.

But in most cases if used for more than a year and depending on the environment it`s used in.

The throttle effect relates to the fact that the fan used to cool the added gpu in the laptop is either not working as it should.

Or there is a thick matte of dust covering the cooing fins of the gpu cooling solution internal to the laptop.
Meaning there is no air flow from the fan passing through the cooling fins.

And the only way to check this is one of two solutions, the first is to open the laptop to access the cooling solution used and clean the matted dust out.

Or where the heat exits the laptop via the vents on the side or back is to use a compressed air canister with a straw to remove dust buildup.

I suggest you try the second option first.
https/www.amazon.co.uk/Cleaning-Keyboards-Dashboards-Computers-Scanners/dp/B006YT69BU

 

[SyMix_KD]

But the throttling is based in gpu core temperature (correct me if i'm wrong) and the temperature does not get that high as you can see in the screenshots, so I think It's not a cooling problem, the temps are really low. In my old laptop for example, only when temperatures reached 95c it would throttle.

 

[SyMix_KD]

Help?