Graphics card or CPU are getting too hot.
At least that is what it appears to be from your description.
Let me see if I can find some monitoring tools if no one else posts them first.
I'm using what came with my ASUS hardware so they won't work with your moboard.
I'll get back to you in a few minutes if no one else does first.
This gives you CPU and GPU temps plus a lot of other info.
SIV - System Information Viewer
You will see this towards top left of column. Left picture below
CurrentReleaseDownloads First one down
siv.zip is what you need. It is not a big download.
After download extract files.
Inside folder you will see a blue magician figure next to SIV64X.exe click that to open.
Then you will see right pic below hopefully with temperatures as mine does. I circled the CPU and the GPU which is the bottom temp.
Hope that helps and works.
Post temps when you get them.
Mike