750W Seasonic G12 GC-750.
That PSU is on the side of low quality. More like between mediocre and low quality. So, not that great. Better would be Seasonic Core series (mediocre quality), while i'd personally suggest Seasonic Focus series (good quality), Seasonic Vertex series (between good and great quality) or better yet: Seasonic PRIME series (great quality).
(My rigs are powered by 2x PRIME and 1x Focus units. Full specs with pics in my sig.)
Wattage wise, you have ample of it. Even 650W unit would be enough. But PSU build quality just isn't there. So, i'd look towards better quality unit.
Other good/great quality units (other than the Seasonic ones i already listed), are: Corsair RMx/RMi/HXi/AXi and Super Flower Leadex Gold/Platinum/Titanium.
PSU may or may not be behind the issue you're seeing. Since it's the ripple (especially high ripple) from PSU, that causes component instability and that instability can cause all sorts of issues, BSoD, system freezes, GPU artifacts, you name it.
So, for system stability,
especially when OC'ing CPU/GPU, you'd want PSU with as low ripple as possible. But cheap/lower quality PSUs just aren't built that well.
That's a good idea tbh, I'll have to do that. It didn't cross my mind, I appreciate it.
This narrows things down quite a lot. Also, with video recorded, you can slow down the video or view it frame-by-frame (e.g with VLC media player) to see what is exactly going on.