Hello, first sorry about my english, i'm french and i my english is very average.
When I lauch a quiet big video game, abetween 5 and 15 minutes after, the fans of my RX 480 go crazy and my screen turn off, so i have to reset my computer (the RX 480 is not very warm, around 50, 60°C)
I tried to re-install the drivers, but it changed nothing, if you have any recommandation, thanks a lot !
You did not mention which driver you are using, but i would recommend uninstalling your current driver and updating to the latest Crimson driver, which was released yesterday 16.11.4.
Once the drivers are installed and you have restarted your system, please navigate to Radeon Settings > Gaming Global Settings > Global Wattman and use these settings.
Max target temp 90
Min target temp 75
Max fan speed 3000
Min fan speed 1200
Power limit +50%
Click apply and see if the same issue occurs.