While playing DOOM, Dark Souls III, and even an older, game like Borderlands 2, my entire system crashes (also crashes on native linux games like Half-Life 2). After waiting close to 5 minutes there was still no response, just a black screen. When the crash happens, the last half-second of audio heard repeats for about three to five seconds and a black screen. I need to power off the system using the power button and holding it down for 5 seconds. It boots normally.
I have tried a few suggestions found on this and other sites. One was to make a swapfile of 8GB which I've done. Another was to try different kernels, which all had the same problem (tried 4.4, 4.9, 4.19, and 5.4 ). I'm sure there was another suggestion but I don't remember what it was.
When playing DOOM, i monitored ram and cpu usage using 'htop' and 'xfce4 Task Manager'. htop showed the system using ~3.5G of ram (with 1, 2, 3, and 4 being at about 70-90%). In htop, the CPU% for DOOM was ~200 when in game, but reached to 300 (i dont know if that is normal or a bug in htop). In Task Manager, the CPU% for DOOM was ~80-85%
I used "journalctl -p 3 -xb" as suggested by another topic to see if there were errors. This was the output.
All games i have played run perfectly until the unexpected crash. In DOOM, Borderlands 2, and Half-Life 2 the crash happens randomly, sometimes thirty minutes in, other times five minutes in. In Dark Souls III, it usually happens when traveling to "Firelink" or other locations.
P.S. I am not too technically savvy so there is a chance of me not knowing what something means, though it is probably unlikely.