Problems with thermal throttling on csgo

[Xicopowa]

So i bought a lenovo y50-70 about 2 years ago and i use it 90% of the time to play csgo.
I connect the laptop to an external monitor, keyboard and mouse.
Specs:
i7 4710hq
Gtx 860m 4gb
4gb RAM
W10

I play on 1024x768/75hz all low settings
My problem is the laptop runs csgo at a steady 150 fps, and suddenly drops to 50-60, i know this sounds pitty and shit but it drives me nuts and i literally stopped playing because of it.
I thought inicially the problem was thermal throtlling so i cleaned the fans, the air exits and intakes and reapplied thermal paste. I refreshed the OS to a clean install only with csgo installed and used Throttlestop to see if it would do anything, and the problem stays the same. I stress tested the gpu at 1024x768 and there was no fps drops and the temps stayed low at 70ºC, so i guess that singles out the GPU.
Since reapplying thermal paste the cpu and pc shell run much cooler than before but the problem still persists (when i first bought the laptop there were no drops).
Wich makes me come here for help, i dont know what else to try.
i'm willing to try anything that doesn't put the laptop health in risk.
I only use this machine for csgo so its a huge hassle for me.
Thanks in advance

 

[MnMWizard]

I'm not sure if you said you were monitoring your CPU, but if you aren't, you should. Download MSI Afterburner select only the temperature and CPU clock settings and watch it while you're playing. If the temps get too high or the clock speed randomly drops, you're CPU is throttling.

 

[Xicopowa]

I also monitored my CPU while stress testing it, it is throttling and the temperatures jump like crazy and are super unstable like one minute its 70ºC the other jumps to 90º then 100º then it throttles , temp goes back to 70º then to 100ºC again throttling. This in just seconds. It's literally impossible that the cpu is at 100ºC that fast the shell is literally cold when in other times it would be almost burning and the cpu was not throttling. I think maybe the heat reading sensor is sending wrong info? Thanks

 

[geofelt]

I suspect that when you reapplied thermal paste, you did not get the cooler on properly.
At idle I would expect the temperatures to be 10-15c. over ambient if the cooler is working and it is mounted properly.

100c. is the temperature that causes the cpu to throttle or shut off.
Can you tell if the cpu cooler fan is spinning?

 

[Xicopowa]

I suspect that when you reapplied thermal paste, you did not get the cooler on properly.
At idle I would expect the temperatures to be 10-15c. over ambient if the cooler is working and it is mounted properly.

100c. is the temperature that causes the cpu to throttle or shut off.
Can you tell if the cpu cooler fan is spinning?

Can confirm the fan is spinning well, will unassemble everything and reapply the heatsink, i mounted it using the cross pattern for the screws but i only pushed them until i felt some "harder" resistance , maybe i should tighten them?

 

[geofelt]

I have no idea how your cooler gets mounted.
In general, it is best to tighten each of the mounting screws slightly, one at a time.

If you tighten one fully, the cooler will not seat well.

Also, how much paste did you use?
Too much will act as an insulator.
A small rice sized drop in the center is all you need.
It is hard to use too little.
It will spread out under heat and pressure.

 

[Xicopowa]

I have no idea how your cooler gets mounted.
In general, it is best to tighten each of the mounting screws slightly, one at a time.

If you tighten one fully, the cooler will not seat well.

Also, how much paste did you use?
Too much will act as an insulator.
A small rice sized drop in the center is all you need.
It is hard to use too little.
It will spread out under heat and pressure.

I used like a pea sized drop in the center and didnt spread
Do you think we can rule out any software related problem?

 

[geofelt]

W10 has been known to update drivers to what it thinks is the latest, but are actually worse performing.

Try reinstalling your drivers directly from the Lenovo download site.
If that fixes the problem, you should be able to tell windows 10 to not download any drivers.

It might also be a good idea to take a user system checkpoint when all is well so you can revert back in case something goes south.

 

[Xicopowa]

I have no idea how your cooler gets mounted.
In general, it is best to tighten each of the mounting screws slightly, one at a time.

If you tighten one fully, the cooler will not seat well.

Also, how much paste did you use?
Too much will act as an insulator.
A small rice sized drop in the center is all you need.
It is hard to use too little.
It will spread out under heat and pressure.

W10 has been known to update drivers to what it thinks is the latest, but are actually worse performing.

Try reinstalling your drivers directly from the Lenovo download site.
If that fixes the problem, you should be able to tell windows 10 to not download any drivers.

It might also be a good idea to take a user system checkpoint when all is well so you can revert back in case something goes south.

Ok so i just screenshotted my game just as i opened it
CSGO

100ºC on 50% usage, something is clearly not right.
Now that you mention it, i tightened the cooler one screw at a time and i tightened them fully.
I will now try the drivers from lenovo,
Thanks for your great help