So, I bought a brand new PC (at least I think I did). It seemed to work fine, unless I started to play some mediocre games. After a half an hour, the PC turned off. Sometimes it restarted on its own, sometimes completely shut down, throwing a "No Signal Input" error on the monitor. The only fix was to underclock my RX 580 4GB to 1198 Memory clock.
But it works only if I have set the maximum state of 1198 on both Adrenalin and msi Afterburner and on top of that, I have tweaked the fan speed to 50% on Afterburner. Without msi Afterburner, it crashes just like before.
Today happened a weird thing, after a month of no crashes, using both Adrenalin and Afterburner, it crashed again after 40 minutes of playing a kind of demanding game (but not that much).
The temperature is normal on both CPU and GPU. PSU is 700W. I use i3 F9100 with 16GB of RAM.
usually that's a power issue. Underclocking lowers the overall max power usage. Some cards can go up to 300+ watts when set to normal. When you get Crashes its because the card starts to request more power because of a game and then fails. In most of these situations running on desktop will never have issues while in 2D.