Here is how to fix stuttering and fps drop in Sniper Ghost Warrior 3:

Check in nvidia control panel in:
Manage Settings 3d --> Check prefered graphics procesor (Must be "processor Nvidia with high performance") --> Apply and check game.

When stil you have lags and crash on good PC check my guide.

Install this when you don't have windows 10:
https://support.microsoft.com/en-us/help/2999226/update-for-universal-c-runtime-in-windows and
https://www.microsoft.com/en-us/download/details.aspx?id=48145

When you have windows 10 install only:
https://www.microsoft.com/en-us/download/details.aspx?id=48145
*[and
Disable windows 10 Game mode (default is on) in system because is bugged and giving poor experience in-games like inputs lags or less fps and lags in desktop when game is "alt + tab" than with changing this to off.]*

When not work try second option:
Update your graphics card/s driver/s:

When Still not work try third option:
Try set virtual memory / page file in system windows to min. 12/16GB and max. 12/16GB.

Or when still not work try last option:
Off your antivirus before start game or start using windows defender. When you off antivirus or you using windows defender and still not fixed try this:
In cfg game write this commands:
Default CFG location: "C:\Program Files (x86)\Steam\steamapps\common\Sniper Ghost Warrior 3\GameSDK" game.cfg
r_SSReflections = 0 - I this problem is for now with this on (sttutering when on I think) - For me this helped with stuttering when I upgraded from 8GB ram to 16 GB ram. When this not helped try this commands:
r_SSDO = 0
r_MotionBlur = 0
r_DepthOfField = 0
r_HDRGrainAmount = 0

Or try change your resolution:
And next when not work try put lower resolution like 1366x768. When not help disable background application like browser - this help alot too.
This tested on notebook '' MSI GL62 6QD' with GeForce GTX 950M DDR3 2GB; procesor I7 and 8 + 8 GB Ram and 4GB virtual memory set in system win 10 64bit. Resolution in-game '1366x768'.
I think I helped ;)

Source for cfg commands:
http://segmentnext.com/2017/04/26/sniper-ghost-warrior-3-pc-tweaks/

My CFG:
r_SSDO = 0
r_MotionBlur = 0
r_DepthOfField = 0
r_HDRGrainAmount = 0
i_mouse_smooth = 0
i_mouse_accel = 0
i_mouse_accel_max = 0
r_SSReflections = 0
r_ChromaticAberration = 0

P.S. I think this game need minimum 12GB memory ram and e.g. 6GB set in disk cache memory in system.

P.S.S. Sorry for my bad English. I'm from Poland.
8GB ram in minimum requirements in-game = 8GB free memory in system / task manager before start launching game.

*virtual memory = pagefile on hard drive
*[.......]* Update from 09.05.20y.