Low framerate compensation
Also called LFC · frame doubling
Low framerate compensation shows each frame two or more times when a game drops below the bottom of a monitor’s variable refresh range. It keeps the refresh rate inside the range so variable refresh keeps working.
A frame rate that keeps crossing that threshold switches it on and off, which is one cause of flicker on variable refresh monitors.
In practice
Every variable refresh monitor has a minimum refresh rate, often around 48Hz. When a game drops below it, the graphics driver repeats each frame so the monitor stays in range. That keeps motion smooth at low frame rates. When the frame rate hovers around the threshold, the switching can show up as flicker or a brief stutter.
How to check
Check your monitor’s variable refresh range on its product page. If flicker or stutter appears only when frame rates drop into the forties, you are near the threshold. Lowering game settings to stay above it or capping the frame rate to a steady value usually stops the switching.