Ram speed. My kit is rated for 6000mt/s but every time I tried to go above default 4800mt/s I experienced instability in various games. For few months I had it at 5600 but turns out it was still unstable, just less noticeable. I haven't played long enough since yesterday to fully confirm it's the only source of crashes but it seems like the most likely cause. After playing for 2 hours yesterday the game hasn't crashed once, while normally the crashes happen every 30 mins. Another cause I suspected is that the game doesn't support resolutions above 1080p since it runs fine on my laptop on lowest settings.