i just did a clean update (DDU) from non whql 17.2.1 to 18.1.1. After that i played a game (Company of Heroes 2) and my Pc just turned off, no blue screen or anything else it was like killing it with the main switch on the power adapter.
I was guessing thermal problems and i did some investigations. I found out that the fan control is very sluggish so i reached 90° C and the GPU begins to throttle his clock speed and a few seconds later my Pc turns off. I tested this with 17.12.2 as well with the same issue.
So now I'm back to non whql 17.2.1 and did the same test, the GPU begins to throttle again but the Pc don't crash, after a while the fan is at a reasonable speed and the Clock is stable at 1330 MHz. Temps are about 80 - 85° C.
It looks like to me the throttle mode in the new drivers is broken.
AMD RX 480 PowerColor red devil @ 1330 MHz, no OC was done by me.
I7 4790k @4.4 GHz Boost
Mainboard: MSI Z97 Gaming 5
16 Gb RAM @ 1866 MHz
Ennermax 600W power source
Win 10 pro 64bit with the latest updates
Dual Monitor setup running.
Gloabal WattMan settings are the default settings.