Continuous DirectX Errors

[Kirika-]

I only have MSI Afterburner to look at the temperature, my computer doesn't offer a built in program to monitor temperatures. Seeing as the temperature never goes over 83, that could be its limit. But even with the fans keeping the temperature below 63 degrees, it still crashes.

Use HWMonitor instead, as it will show all devices' temperatures plus wattage used per device/core.
https://www.cpuid.com/softwares/hwmonitor.html

Also, the Asus Aegis II software is kinda messy when dealing with DirectX programs.
FF14 runs in DX11 (or DX9 if you switch it to that) and one thing that most video cards do not like to do is to display more than one DX version at a time. Some of Aegis programs run in an overlay, which might run in a different DX version than the game is running under certain circumstances, which might cause the crashes.
If you don't actually use all the Aegis features, it's best to uninstall it....cause with the exception of a couple features, it is really just bloatware.

[viaharbinger]

Progress update! While I haven't tried anything stressful ingame recently, I've managed to finish the SHB benchmark without crashing. All I've done since then is crank the fans to 95% and relocated the tower to sit on its side on a desk. Tried this a few times to then tried it without the fan and it crashed in the third cutscene. I've tweaked so many things at this point I could be forgetting something. Guess all this points to overheating, but I'm not sure how to fix that more than I already have without opening the tower. I'm not sure if I can rely on it for say farming e6s (it used to crash so badly in phase 2) but I'll be looking into how it handles ingame stuff coming up.