I was playing modded Oblivion (yes, I still play it!) and noticed that the sky seemed to occasionally be flickering a solid black for a frame. (Yeah, the game seems to run properly once again on Windows 10 systems. Seems like something got patched) As it seems to do that even when running it without mods to rule out misbehaving mods, figured that maybe I should try running some other things to see if it does strange rendering.
Sure enough, although Unigine Heaven appears to run fine, sometimes the lens flare pops up for a frame in obviously incorrect locations. I'm pretty sure I'm not supposed to see it when the only bright light is behind the camera, while viewing the entire floating islands in night at part of the looping scenes... or maybe some object decides to flicker momentarily.
Note that the video card is currently already running at its factory overclock and no more, and temperatures appear to check out - it tops out at 71 degrees Celsius, the GPU fans never going past 50%.
I sure hope I'm just imagining things, as I kind of am shuddering at the thought of waiting a long time for warranty returns. Downclocking might help rule things out, but at some point it probably isn't much of a GTX 970 anymore, isn't it?