The resolution of the view, number of pixels per second, is more to do with the performance of the GPU. A 4k capable GPU would be able to display 4k at the refresh rate of 60Hz, no matter what the game or simulator.

With the amount of content in the simulation window, that changes the requirement of performance for the CPU. Let's say we zoom right out to see the maximum view angle, we see the most things at once, that's a problem for the overall performance of the system and CPU.

Using Locked fps and VSync=On causes long frames on every frame that does not complete inside the time for the frame, that is a form of stutter

With Unlimited VSync=Off, the view is always synched to the monitor so although we don't see full on tearing, we do see parts of the view shifted in turns or panning. That's possibly less frustrating than VSync=On with Locked fps getting long frames where we would use it usually below 30.

Enable shadows is a problem, can half the fps. With wide view, shadows and low down in the airport, medium to high settings, we don't expect to hit 60fps on current hardware. The fps capacity of the GPU is down to the part number.

 

Sorry for necroing (I hope being the OP will cut me some slack). Recently I've started seeing lots of blurries in my setup. My current setting is with FPS unlocked + RTSS in Scanline x/2 (thanks to you all). It's smooth, but easily goes blurry. After not bearing the blurries anymore, I tried the following:
1) 30 FPS lock + RTSS in Scanline x/2: crisp, but stuttering a lot.
2) 30 FPS lock + FFTF=0.10 + RTSS in Scanline x/2: crisp, and almost as smooth as in my current settings.

However, the other day I ended up in fullscreen mode and saw some serious tearing that RTSS did not fix at all. I decided to compare RTSS in Scanline 1x with D3DOverrider (with Vsync and Triple Buffer set). Leaving FPS unlocked in both, not only D3DOverrider was actually smoother than anything I may get with RTSS, but also the tearing disappeared. So, in conclusion, this is actually the very first time I've ever seen actual Vsync in action.

Now, although now I have a good option to live with (#2 in my list before), I insist: does anybody know how to force true 1/2 Refresh Rate Vsync in a Win10 laptop for FSX? Nvidia Inspector does not achieve anything, and I can't change my laptop display's refresh rate to 30 Hz.