100% Utilization on One Core

I have been experiencing a problem recently. Upon launching the game, there is an even distribution across the cores of my processor (AMD FX-8350 8 Core with GTX 1060 6gb GPU). Upon playing for a length of time (it varies between 5 minutes or several hours), the cores utilization changes to only one core maxed at 100%, while the others sit at 0-2%. This drops fps into the single digits. The rest of my computer works fine while this is happening, with it being able to open other programs or games and they perform without issue. CPU temps stay under 30 C and GPU around 60 C, so it does not appear to be a heating related issues. I have reinstalled ffxiv and done clean installs of graphics drivers.

Any help is appreciated.

Good morning and thank you for posting on the Final Fantasy XIV Technical Support Forums.

The game doesn't seem to be able to utilize all of the cores you have. When did this start happening? Did anything change/update on your PC that coincides with this?

You mentioned this happens after a set amount of time, does the location in the game affect it at all? Does selecting DX9 mode have the same issue?

There is something I'd like you to check. Open the Task Manager (Ctrl + SHIFT + Esc) and go to the 'Details' tab. Find Final Fantasy XIV (It should be listed as 'ffxiv_dx11.exe' or 'ffxiv.exe') and right-click it. Select 'Set Affinity' and makes sure all the processors are selected (you should see '<All Processors>' and 'CPU 0' through 'CPU 7' for an 8-core CPU).

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!