Question Related problems with Gainward GTX 1070 Phoenix and Asus R9 200?

Sep 3, 2021
Nearly a year ago the GPU stopped working. The monitor would go into standby and the GPU would just blink: View:

When that had happened I also needed to do a reset (via button) of the PC which led me to assume that the os (win 10) also stopped working. Since a check of the temperature didn't show anything unusual and it also happened when doing nothing (5 to 25 minutes after starting the PC), I thought it just died (was 3 years old back then).

Someone had a Radeon R9 200 lying around, so I'm using that. The problem now is that when playing certain games (it seems all of them use Unity like Pathfinder Kingmaker, or even Rising Star 2 - masochistically tested it by playing it for a few hours) the pc reboots more or less (most of the time while quickloading in the case of PF, and when loading gigs in the case of RS2) randomly (showing the 6008 ID in the Windows event-log). Since the temperature of GPU and CPU is normal and I don't have that problem with any other games (like Mount&Blade Bannerlord or Crusader Kings 3 for example), I wanted to make sure that there isn't any obvious connection between the 1070 problem and the R9 200 one before even considering buying an overpriced new GPU and potentially damaging it.

PSU: Dark Power Pro P11 550W
RAM: Corsair Vengeance LPX 16GB DDR4-2133 Quad-Kit
CPU: i7-6700K (with Scythe Mugen 5 cooler)