Matt, could you try the same settings I'm using. 1120 core with undervolting (I use -12 mV). I can run 1150 with overvolting, but undervolting with lower core gives me better score always. And I do have +50% power settings in use.
I believe it could be vrm's overheating.
Matt, could you test native 4k with 8xmsaa on single card with dx12 vs dx11. Just wanna see how the memory handles. As I'm already using all 4GB of my card on 1080p at 4x msaa. If I'm right you should be getting stuttering on dx11, but not on dx12 because 12 handles memory totally different.
Yes will do next time I'm doing another run.