Video and displays
Input lag
The delay between a signal arriving at a display and the corresponding image appearing on screen, critical for gaming responsiveness.
Input lag is the time a display takes to process and show a frame after receiving it. Motion interpolation, noise reduction, and upscaling add delay; game modes bypass most of it. It is distinct from pixel response time, which is how fast a pixel changes once told to.
For film and TV, lag is irrelevant as long as audio stays in sync, which lip-sync adjustment handles. For games, it directly affects how connected the controls feel, and more than a few frames is noticeable in fast titles.
Good game modes measure about 10 ms at 60 Hz and 5 ms at 120 Hz; under 20 ms is fine for most players, while 50 ms or more feels sluggish. A receiver in pass-through should add well under 1 ms.