SSAO & VSYNC what does it actually do?

[ZaltysZ]

Vsync makes sure VGA gives no more frames to display than it can show, and syncs showing of frame with display refresh, so that you won't see 2 frames at once. Vsync removes tearing.

SSAO is ambient occlusion. It simulates light attenuation due to occlusion. AO gives so called soft shadows and makes image more real life, however usually effect is very subtle and hardly noticeable, unless you know where to look. It easily can eat 30% of FPS, so it is better to disable it in flight sim.