GPUPC experiences instability when the GPU handles heavy tasks
GPUPC experiences instability when the GPU handles heavy tasks
The random issues and decreasing stability remind me of RAM problems, so I suspect your VRAM could be failing. If your system can't consistently produce output with the card, the best options are either try another card on it or test this one on another machine. Checking if the card still works at any level suggests the GPU is likely fine, leaving board components as the next possible cause.