My system is running at 2.3 GHz rather than 3, but I would have expected just a slower frame rate, rather than constant crashes. I did turn down the scenery complexity, but no luck. When it runs, it looks good and flies well.
Last time it crashed, I had opened the program, and left the default Cessna 172 parked on the runway while I entered a flight plan, and probably five minutes in, down it went. I was also watching the task manager, and memory was about 2/3 full, with x-plane taking from 1.5Gb to 3.3 Gb.
Haven't yet downloaded x-plane 10. That might have to be the next step, but it's hard to believe my system is so pitiful 11 won't even run.... (?)