Yes, this could be a motherboard problem, however, unless you replace your motherboard with an exact model Microsoft will want to charge you for a new key to run Windows OS. Usually contacting them and telling them your motherboard died and had to be replaced and you could not find an exact model replacement they will let you have a free key, however, they are not required to.
What is interesting is that cleaning up Windows via the links I provided helped, that is a software issue.
There are several things that can cause your game stuttering issues, some software some hardware related. Sometimes solving a problem is difficult, at least sometimes time consuming, when I have my hands on the computer and is compounded when troubleshooting at a distance, so please try to be patient.
As I mentioned earlier I try free things first.
1.) Download DDU - Display Driver Uninstaller, install it and put a shortcut link on your desktop.
http://www.guru3d.com/files-details/display-driver-uninstaller-download.html
Download Nvidia video card driver. [Do not use GeForce Experience]
Enter Windows Safe Mode, this is done differently depending upon what version of Windows you are using
https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode
Prepare to install video driver in Windows Safe Mode. [Do not use GeForce Experience]. Run DDU. Then install Nvidia drivers, chose Custom (Advanced), leave a check mark only on Graphics Driver, HD Audio Driver and PhysX System Software.
You can put a check mark in Perform a clean installation.
Make sure you have installed all motherboard drivers and drivers for sound, either on motherboard sound chip or an add-in card or daughter card [in a PCIe slot for example]. You should be able to install these in a regular Windows boot up. No need for safe mode for those drivers. Do not install any unnecessary software [much of it is crapware and causes problems.]
Enter Windows normally. Bring up Device Manager and make sure there are no conflicts, especially with sound. That can cause problems with game frame rates.
Run a game and look for imporvements.
2.) Go to the link I provided in my above post and see if upgrading the BIOS works.
https://us.msi.com/Motherboard/support/Z170A-GAMING-PRO-CARBON
Note that there has been a serious bug in Intel CPUs for the last several generations, at least since the 3000 series, and a micro code fix will be in motherboard BIOS updates [it will be a updated CPU microcode probably followed by a suffex], RAM is not the only issue updates address, many problems are fixed. Follow instructions for BIOS updates at motherboard web sites. That bug can be exploited and cause massive problems.
Let me know if the latest BIOS update fixes your problem.
NOTE: There is a lot of information here and I hope I included all of the steps and links. I left out a lot of unnecessary complex jargon that would make this post much larger and more mental workload on you.
EDIT: I forgot to ask, what monitor and refresh rate are you using?