I have an XFX Radeon R9 390 8GB. This problem only started occurring yesterday. However after a few minutes of playing Rust, I get some black artifacts appearing. And then a few seconds later, all of a sudden the graphics card cuts out entirely. No video output on either of the DVI or HDMI outputs. The fans continue to spin however, just at a lower RPM.
As far as I am aware this issue hasn't been caused by a game update, as the issue appeared before the latest major update and I've played issue free since the last minor update.
I ran GPU-Z and started logging however, and took a few screenshots. I've also tried running the game in all Direct X modes (9, 11, and 12). The GPU load appears to be at an almost-constant 100% and the temperature getting in excess of 80C in some cases. I cleaned out the case and GPU, that didn't solve the issue. The airflow should be fine in the case. I've been using it for well over a year with no issues.
The GPU-Z Sensor log is also attached.
I've tried everything I know to figure out the issue with no avail. Please help!