I have installed the demo of X-plane 11 and as one of the requirements is a CPU of 3 GHz and I have it of 2.8, they warn that a test must be performed in lower PC's.
Although it is a Beta, X-plane also warns that there are problems of fps that they work on to solve.
In my case: the program does not crash with the settings to the minimum, with this settings, I get 10 fps wiht continous stuttering. After serching in the net I have found some NVIDIA settings that go up to 20 fps and with almost imperceptible stutter. However the simulator with these minimum settings is not visually usable.
Here are the settings in Nvidia Inspector:
Multi-display / mixed-GPU acceleration:
If only one monitor is used: Single display performance mode (if two: multi)
If multiple PCs are used each with their own monitor: Multi display performance mode
Power management mode: Prefer maximum performance.
Threaded optimization: OFF (this is the most important)
If you use multiple PCs each with a monitor, in addition to applying the above to each PC, you'll need to match the synchronization, in 2 - Sync and refresh, in Vertical sync put 1/2 refresh rate.
In my case: The next step is to make graphic adjustments that affect only the GPU: Visual Effects, Texture Quality, Antialiasing, with medium settings, the other CPU intensive at minimum. I'm still at 20 fps with very small sporadic stutters. I need to wait about 30 seconds to reach 20 fps before starting the flight.
I hope it helps those trying to work with X-plane 11 and improve those with use X-plane 10.