Wow, what the fuck Gigabyte. Apparently when my motherboard gets power backfeed via a dodgy DisplayPort cable, it doesn't like, warn me about it, or have any sort of backfeed protection.

Instead, it just starts being unable to reboot without a hard power cycle, *and* starts reading the CPU temperature as permanently -55C (no, that's not a typo), causing it to completely disable the CPU fan regardless of actual temperature... which was up in the mid-90s.

On top of their (shitty) fan curve smoothing option only being exposed via a crappy Windows app and not via the EFI.... yeah, I ain't gonna be buying Gigabyte again 😐