Poor performance from a high-end build?

[Vehn]

I'm just gonna say that even when you have super power GPU, it's not use if your CPU can't match your GPU

You need your processor to feed the data to GPU.
Without the CPU that capable to feed data to your GPU at it's ability, then the GPU just gonna have to settle down to your CPU thus your low FPS

That say, that some game that you mention are High GPU, Low CPU type of game
But some game like FFXIV are the type that High CPU, low GPU type of game

so unless you upgrade your CPU to match your GPU, i don't think you gonna see any improvement

--Other people offering you suggestion for the parts to change, i'm offering explanation as to why it works like that