Witcher 3 lagging

[manllama]

Hi all. I have just bought and built a new gaming pc. Specs are:

• 
  i5-6600k
  Asus GTX 980
  Asus Sabertooth Z170 Mark 1
  16GB DDR4
  Corsair RM750x
  Windows 10 64bit

When I start Witcher 3 the video and mouse lags. When my mouse click finally registers (takes about 8 - 10 seconds), and I manage to start a new game, everything continues to lag terribly.
I have already trawled the net for answers, but none have worked.
I have turned down all game settings.
I have installed latest nvidia driver, and oldest driver I could find on nvidia site.
I reinstalled both drivers again, in case of install error.
I tried to force W3 to use my GTX 980 in the Nvidia 3D settings, but the option was not there.
I have disabled my onboard gpu in case that was being used instead.

Does anyone have any other suggestions?

Thanks in advance.

 

[Supernova1138]

Does this happen in any other games or just Witcher 3? If this is happening across all games, that indicates a larger problem like thermal throttling on either the GPU or CPU, power issues, or some weird software problem related to your Windows installation.

It might help to post which power supply you have, and check your temperatures with a program like HWMonitor. Also make sure your monitor is plugged into your graphics card, if it's plugged into your motherboard, you're using your integrated graphics and the Intel HD 530 IGP isn't going to do very well in Witcher 3.

 

[manllama]

I have added my PSU to the OP (RM750x).
I definitely have all monitors plugged into the GPU. I even disabled the integrated graphics.
No other games have been run yet. I've been so focused on W3. I will test out some others tonight. I'll also give that HWMonitor a go.

 

[manllama]

I ran Shogun 2, Portal 2, Saints Row 4 and Tropico 4, all on highest possible settings. I know the latter 3 games aren't particulary gpu hungry, but they all ran really well. Shogun 2 was beautiful! I'll be playing a lot of that now. Seems like Witcher 3 is the problem.

 

[Supernova1138]

You might want to try reinstalling the game or verifying the game files. The only other thing I could think of is your Nvidia driver being stupid and not increasing the GPU clock when Witcher 3 runs, so forcing it to Maximum Performance mode in the Nvidia Control Panel when Witcher3.exe is running might be something you might want to try.

 

[manllama]

You might want to try reinstalling the game or verifying the game files. The only other thing I could think of is your Nvidia driver being stupid and not increasing the GPU clock when Witcher 3 runs, so forcing it to Maximum Performance mode in the Nvidia Control Panel when Witcher3.exe is running might be something you might want to try.

I have verified the game twice and changed that Nvidia setting to "maximum performance". Still no improvement.

I have also noticed that in the main menu the video practically stops when I move my mouse. Something similar happen in-game. If I keep the mouse still, the game will still lag, but as soon as I move the mouse, everything stops.
Any ideas?

Heres a screenshot of various monitoring programs forums suggested:

Does this show any problems?
Thanks again.

 

[manllama]

So, after all that, it turns out to be GOGs game overlay

I disabled it and Witcher 3 is running perfectly. 😀

Thanks for all your responses.