Managed to reduce it by setting a fps limit with Precision OC.
 
I Have a 100hz monitor, i set 98fps limit and seems a bit better.

Vsync on
Gsyn on

I really don't think it's about the drivers.

Seems it more a gsync issue

Good work cutting that signature down

Many people get confused whether or not to enable VSYNC with GSYNC or to disable VSYNC because of the worries of increased input lag. The reality of this is that VSYNC should be set ON in your global nvidia control panel settings when using GSYNC. Tearing can actually still occur if VSYNC is OFF when using GSYNC - even if you are within GSYNC's operable range. The reason for this is that when VSYNC is off it disables GSYNC's ability to account for frametime variances. Input lag will NOT be affected when VSYNC is enabled with GSYNC unless your game FPS hits your max refresh rate, then plain old regular VSYNC will kick in. To get around this, use a framerate limiter like RTSS to cap the FPS in your games at about 3-5 FPS below your max refresh rate. This will ensure you always are using GSYNC for the best results possible. VSYNC should be OFF in game settings however so no conflicts can occur.
 
For an in depth analysis on this, read this very thorough but informative article: https://www.blurbusters.c...ag-tests-and-settings/
 
From the article:
G-SYNC + V-SYNC “Off”:
The tearing inside the G-SYNC range with V-SYNC “Off” is caused by sudden frametime variances output by the system, which will vary in severity and frequency depending on both the efficiency of the given game engine, and the system’s ability (or inability) to deliver consistent frametimes.
G-SYNC + V-SYNC “Off” disables the G-SYNC module’s ability to compensate for sudden frametime variances, meaning, instead of aligning the next frame scan to the next scanout (the process that physically draws each frame, pixel by pixel, left to right, top to bottom on-screen), G-SYNC + V-SYNC “Off” will opt to start the next frame scan in the current scanout instead. This results in simultaneous delivery of more than one frame in a single scanout (tearing).
 
G-SYNC + V-SYNC “On”:
This is how G-SYNC was originally intended to function. Unlike G-SYNC + V-SYNC “Off,” G-SYNC + V-SYNC “On” allows the G-SYNC module to compensate for sudden frametime variances by adhering to the scanout, which ensures the affected frame scan will complete in the current scanout before the next frame scan and scanout begin. This eliminates tearing within the G-SYNC range, in spite of the frametime variances encountered.
Frametime compensation with V-SYNC “On” is performed during the vertical blanking interval (the span between the previous and next frame scan), and, as such, does not delay single frame delivery within the G-SYNC range and is recommended for a tear-free experience (see G-SYNC 101: Optimal Settings & Conclusion).

Asryan
Hm ok so best setting would be

Gsync ON
Vsync on in NVCP and off in game?
And a FPS limiter to refresh rate. Is the one from precision OC good or RTSS is better,

When i use the FPS limiter i don't see that flicker anymore or not so noticeable. 

Nobody has tested with precision, so just use rtss.

Asryan
Seems that the flicker issue with gsync occurs when i have vsync on in NVCP. Not on all games but mostly

Is there a solution?.

it's kinda like on this video
https://www.youtube.com/watch?v=8rvY_jDIgQI
 

When using Gsync and Vsync combo (recommened), make sure you use a frame limiter set to a min of 3 FPS below your monitors refresh rate.  Post #8 above has some good explanations.
 
Also, if you're running PXOC, try turning off all OSD items and don't have the graph open.  See if that helps anything.

Apparently the issue is commun on lot of monitors. Weird.. it disappears when i turn vsync off but then i'll get some tearing..

Asryan
I tried different settings and got rid of the issue in most games by disabling completely vsync but I read on different topics that it was not the best setting for gsync and vsync was needed to run with it.
https://www.blurbusters.com/…/gsync101-input-lag-tests-…/14/
Moreover, i got some tearing in game.
I finally tried to use fast sync in nvidia control panel + RTSS to limit my FPS to my refresh rate minus 2 (it's useless to have my GPU work with 200 fps if my screen can only display 100 right?)
So i was wondering do you see any flaws in that solution? Never used that fast sync before and i was wondering if that will cause any issues of input lag or whatever?
Thanks for your advice

Correct.  Running FPS over your refresh rate doesn't do much good in most cases.  As far as using Fast Sync, since you're capping your frames just under your monitors refresh rate, fast sync won't come in to play.  That is used to minimize tearing when you're running over the refresh rate of your monitor.
 
As long as you're running below your monitors refresh rate, then Gsync will be doing all the work as far as syncing goes.

At this point, I would suggest using whatever setting works best for you and your system.  You have all the info you need in this thread as far as the best/most recommended syncing solution.  It just seems to me that if you're having this issue in all the games you play, either it's your monitor with some kind of defect or your eyes are very sensative to this issue.
 
Beyond that, I'm not sure what else I could suggest...