What is NVIDIA In-Game Overlay?
NVIDIA In-Game Overlay is a feature that comes with NVIDIA GeForce Experience application. This feature provides such as ShadowPlay (NVIDIA Screen Recorder with lossless FPS), FPS Counter overlay, live broadcast services (with the camera, viewers, and comments overlay).
Sadly, this feature only available for GeForce GTX Desktop GPU 600 series or higher and GeForce GTX Notebook 660M or higher. Even if your NVIDIA Graphic card has a better performance than i.e GTX Notebook 660M, you can't enable this feature. But don't worry, you still able to use this feature but you might unable to use screen-recorder or live broadcast features on NVIDIA In-Game overlay.