Greetings fellow Eorzean,

I'm sorry to hear of this issue you are currently experiencing with high disk usage and BSOD when playing FINAL FANTASY XIV. This may be due to a variety of issues, and may be difficult to pinpoint what the cause may be. It could be due to a hardware or driver issue on the PC. Have you updated or reinstalled your graphics card drivers to make sure they are up-to-date? It may also help to update your Windows operating system, and install any optional updates that aren't automatically installed as well. Lastly, have you tried a full uninstall and reinstall of the game? We would recommend to install the game on your PC's primary drive, if it has yet to be installed there.

We hope we can be of assistance with this. Thank you for posting in the FINAL FANTASY XIV Technical Support Forums!