I recently built a Ryzen build with Ryzen 5 2600 and Gygabyte RX 580 8gb. I installed windows 10 pro and then problems started to acquire. At first I experienced blackouts when playing games in fullscreen, the pc wasn't shutting down, the sound was still on and the game would still be running. These blackouts lead to more blackouts (those blackouts lasts for about 1-3 sec.) every 5-10 mins, afterwards purple screen kept appearing when going into fullscreen, extreme screen tearing etc.
Fast forward I couldn't play any games in fullscreen because the screen would just go black I immediately contacted my seller and I got my gpu replaced with the same model. The problem seemed to be gone, but it came back after 5-8 hours of computer use. Then monitor went black for couple of seconds not only when I was playing a game in fullscreen but when I was watching a video on Youtube while fullscreen. I found that those blackouts dissapeared when watching a video without hardware acceleration.
With new video card in my pc I DDU'd my gpu drivers, searched all internet for fixes, cleared cmos, uninstalled MSI AfterBurner, tried different PCIe slot and nothing helped. Today I turned on my pc and for some reason I wasn't getting more than 30 fps on any game. After downloading AfterBurner I found out, that windows shows video card usage 100%, but gpu clock speed stays locked at 300mhz and won't go above. My cpu won't go above 15% usage either. I reinstalled windows and the problem with locked clock speed went away but I still experience blackouts. Now I'm completely lost, I have never experienced a problem I couldn't solve and I hope I find the solution here