CPU or GPU?

[Enlial]

When I upgraded from a i980x (a cpu from 2010~) to a much more modern and powerful i7-6800k, there was some difference in the game but I wouldn't call it major. I suspect that the motherboards chipset architecture matters far more than the cpu itself.

When I added a second geforce 970 to my system there was major improvement (though unless you've got a uhd, 4k or 144hz monitor, I think a single 970 can handle anything this game can throw at it with only rarely dropping to less than 60 fps)

Ive heard that ffxiv is more cpu intensive than other games. I have no idea if thats true or not, but on the other hand, Ive seen a lot of gaming rigs where people will spend thousands and thousands of dollars on graphics cards, and $200 on the cpu. Consensus is that high end CPUs are overkill for gaming.

Short answer: GPU, probably by a long shot.

(also get an SSD if you dont have one. its night and day in terms of load times)