Random FPS drops and sound stuttering

Hi,

I have 30+ hours in Witcher 3 and suddenly verytime when I’m running the game for ~2 minutes game starts randomly dropping from 50 fps to 18 fps with sound lag and I never experienced that before.

Here is example: https://youtu.be/vznNnuIoahA

You can see it better in 0:22 when I’m running.

This is screen of TM when the game is alt+tabbed: http://s9.postimg.org/rg6f58427/Untitled.png

Also when I’m starting the game my CPU is on 0%. I tried to play other HW demanding games like Evil Within, GTA V… for example and never experienced that.

My specs:

i5-4210H

GTX 960m – Latest drivers not updated but installed after Win reinstall which was done this week.

8 GB ram

Windows 10 pro

Can someone help me please? I really like this game and now it’s unplayable for me

Random FPS drops and sound stuttering