Close to 300 flight hours, not a single CTD yet. AMD Ryzen 3970x with RTX 3090 here on a 1000MBit glass fiber line, quite good specs but nothing special.
- Did you try a fresh Windows10 install? If the problems are still there, it is most definitely a hardware issue.
- My bet #1 is a faulty memory. Did you perform long running load tests?
- Another thing to check out is Resplendence Software - LatencyMon: suitability checker for real-time audio and other tasks. Yes, it is for pro audio people, but it can help you finding bottleneck drivers and/or services in your system. When I was a beta tester for MSFS, I had some issues with a professional audio card using ASIO, which could not be set below 64 samples buffer without CTD. Guess this is not your situation, but who knows.
- Cooling? Everything running fine? HWInfo will tell you everything you need to know.
- Regarding internet connection speed, I would not think that this is an issue. I can throttle my connection over a proxy down to a few kB/s, and can still fly.