Windows 10: FPS drops when playing Minecraft in Full screen

Yesterday I updated my driver. Everything was fine, like Youtube and other apps, but whenever I try to open Minecraft in Fullscreen, my Fps drop to 2-10, and if I switch to windowed everything works properly.
I have a «GeForce GTX 1060 6Gb» graphics card.




***Modified title from: Fullscreen Lag after driver update.***

:)

 

FPS drops when playing video in background

I am trying to understand why I experience FPS drops in demanding games when a video is playing in background and how to fix it. My particular setup (see the specs at the bottom): two monitors in extended desktop mode, the primary monitor connected via DisplayPort to an AMD R9 390 video card, the other via DVI alternatively to the on-die Intel HD 4600 graphics output or to the R9 390's DVI output.

I will demonstrate the problem with Witcher 3 game, but the same problem occurs with at least one other game that I tried - World of Tanks (which is where the issue actually matters, as sometimes I put on music from YouTube while in game). In all the experiments below I run Witcher 3 on my primary monitor in windowed full-screen mode and measure the FPS in it with FRAPS. To guarantee stable FPS, I put the game on pause (by pressing ESC). I also set affinity of the Witcher 3 process to the first 3 cores and set the affinity of other applications to the 4th core. The CPU load has remained stable on cores 1-3 throughout the tests at 45-50%.

Baseline test when the game is not running: CPU load is at ~0% on cores 1-3 and ~5% on core 4.
Baseline test when the game is running, but no video being played in parallel: stable 58 FPS, CPU load: ~10% on core 4.

First batch of tests: the secondary monitor is connected to the R9 390.

1. 1080p YouTube HTML5 video running on the secondary monitor (in
   Chrome or Firefox): ~48 FPS, CPU load: ~50% on core 4.
   
2. The same YouTube video running on the primary monitor on top of the game:
   same results as in (1).
   
3. SMPlayer playing a 1024x426 AVC video on the
   secondary monitor: ~48 FPS, CPU load: ~25% on core 4.
   

Second batch of tests: the secondary monitor is connected to HD 4600.

1. 1080p YouTube HTML5 video running on the secondary monitor (in Chrome or Firefox): ~44 FPS, CPU load: ~50% on core 4.
   
2. The same YouTube video running on the primary monitor on top of the game: ~48 FPS, CPU load: ~50% on core 4.
   
3. SMPlayer playing a 1024x426 AVC video on the secondary monitor: ~50 FPS, CPU load: ~25% on core 4.
   

Now, one thing I noticed is that performance varies depending on whether the game window is focused or not. The benchmarks above are given for the case when the game window is focused. If the game window is focused, I see clear choppiness in video playback (both in YouTube and in SMPlayer). If another window is focused, video playback is smooth, but game FPS drops more.

My specs: Windows 10 x64, Intel i5-4690K, Gigabyte Z97-D3H, 8Gb RAM, R9 390 video card. The primary monitor (connected to R9 390) runs at 1920x1200, the secondary at 1600x1200.

EDIT: I took a music-only YouTube and tried to play it in various resolutions from 240p to 1080p. The FPS dropped gradually from 58 to 48 FPS as I increased the resolution.

 

Mouse Lagging When Playing Minecraft (FPS Drops A Lot)

When I Play Minecraft I Get 1000 FPS Which Is A Lot But When I Got My New DeathAdder Mouse. I started to lag not because of the mouse that
I realized that it is from my USB that is being messed up. I tried doing many things to fix it like updating graphics card or mouse and
removing Cortana I also tried using task manger to set Minecraft to high
and render to 2 still did not work. I tried plugging my mouse into my other computer and it worked perfectly, the only major difference is that my computer is Windows 7 and my laptop (this one) is Windows 10.

 

Sudden FPS drop/Stutter

Since 2 days ago, I just turned on my Computer, and it starting having issues while I was playing Witcher 3 (starts with decent fpsm and then very low fps, dropping to 35, then 20, and stopping at 12 or so, in a matter of seconds, in a matter of 1min of starting the game), also stuttering without any high demanding programs, randomly. I was playing at 45-60 fps, without any stutters or sudden fps drop. Have tried other games the issue persists. Even setup everything to low settings.
I have ran several tests with several tools, all seems normal, no sudden memory spikes, or temperature raising out of the ordinary, nothing that would indicate such an fps drop or stuttering.

MSI Afterburner

I also did the reset option on Windows10, completly cleaned out all my personal info from the windows partition.
So at this point, I am not sure if it is a software issue or a hardware issue.
Any suggestions are greatly appreciated.

Edit: I kept doing some tests to find out the issue. And this happened before and I was able to replicate it. Same thing happened as before, till I set it up to fullscreen, Alt+Tab from the game and then back to the game, FPS went up to 50 again, stable and good, dropped after a couple of seconds. After a bit it went to 2-5 fps, and I had to shutdown the game, because even the sound was getting messed up.

MSI Afterburner 2

In this image those ups and downs in the GPU usage are when the fps dropped really hard and the sound got messed up.