Confused!! I thought FSX came with a frame rate ajuster, why the need for something else?
I'm sure someone will explain it better.
It's considered a "mileage may vary" solution for some folks to the st-st-stuttering issue in FSX, especially when flying close to the ground.
For some folks using the internal frame rate adjustment in FSX works just fine.
For others, setting FSX to "Unlimited" and using an external frame rate limiter offers smoother performance.
The "experts" are divided on this issue.
I found that using the external frame limiter does offer smoother performance for my system, as I am one who operates very close to the ground in FSX, i.e. helicopter operations.
I do have an nVidia card, and found that the frame limiter in nVidia Inspector works better than some external frame limiter programs, in my experience with my system anyway.
Even in some heavy scenery areas, like Aerosoft's Manhattan X, my FPS still drops, but it has smoother performance which is great when your trying to land on a pad at the Port Authority, Downtown, for example.