I have an all-new PC with nice parts, Windows 10, all the latest drivers and software.
I did not change any settings on the 6900 TUF. I have benchmarked it and done thermal tests, and it runs really cool. I keep the temperatures monitored at all times and pay attention to fan speeds. The card is not overheating.
I made a huge custom Civ 6 game and maxed out all the settings, and played it for a while. It went several hours with no issues. Then, after many hours, the video signal cut out. The PC did not crash - just the GPU. It was not a software crash - the video signal stopped being sent, and the rest of the PC stayed on. I restarted and checked for abnormal temps and found none. I resumed from an autosave, and the same thing happened a few minutes later - loss of video signal, all other parts continue running.
As I said, I kept an eye on the temps the whole time. The room is cold, the case has 7 external fans, VRM fan, two RAM fans, and everything is underclocked except the GPU. It wasn't overheating.
Is this a known issue? What is the cause?
The minumum requirenent psu for the 6900 XT is 850W, using independent cables for the power delivery from the PSU to the graphics card.
System shutdowns usually indiciate a insufficient or faulty power supply, or perhaps overclocked or overheating components.
I'm using a 1000W PSU and 2x8-pin connectors.
The card draws 275W under load. There are hundreds of watts of extra power.
I'm running a RX5700 and my Civ 6 games have been doing it recently too. Like you no overheating - game just stops working. Can run for hours sometimes and others not.