When the gpu falls off the bus, Xorg goes into loop consuming 100% cpu on one core. Also, the gpu goes into an emergency mode, spinning the fans to 100%. So it’s a rather normal behaviour under that circumstance.
Please also check if you have this Seasonic model:
https://knowledge.seasonic.com/article/20-focus-plus-and-gpu-potential-compatibility-issues
You can try mitigating it by limiting clocks using nvidia-smi
https://forums.developer.nvidia.com/t/quadro-rtx-6000-causes-hpe-server-to-power-off-peaks-way-over-power-limit/72215/8