Adaptive vsync is the idea that rather than the monitor having a fixed vertical refresh rate and the graphics card synchronizing to it (if you want to avoid screen tearing), ie. the monitor deciding what the refresh rate is, and the graphics card obeying it, we do it the other way around: The graphics card decides what the refresh rate is, and the monitor synchronizes to it. Which means that the refresh rate can be variable. This means in practice that if at some points the game you are playing drops its rendering speed to eg. 53 frames per second, rather than dropping to 30 FPS because the monitor can't handle anything else, the monitor will now use 53 FPS. Or, in other words, the next rendered frame is always shown as soon as it's ready, rather than the system having to wait for the next monitor vsync to show it. The rendering speed can vary from frame to frame, and it doesn't matter: The image will be shown immediately when it's ready (up to the maximum refresh capac...