Wirebook › Glossary › Input lag
What is input lag (and what causes it)?
In one sentence: The delay between pressing a button and seeing the result on screen, made of the controller, the connection, the game's frames and the screen added together.
A little more
Input lag is the time from pressing a button to seeing the result on screen. It is a stack of small waits: waiting for the controller's next report (polling), the trip by cable or radio, waiting for the game's next frame, the game working out and drawing the picture (often one to three frames), and the screen processing and showing it. A typical console game lands somewhere between about 30 and 150 milliseconds in total.
The biggest pieces are usually the screen and the frame rate. Many TVs add 50 to 100 milliseconds of picture processing, which game mode switches off, and a game at 30 frames a second waits twice as long per frame as one at 60. Input lag is different from online lag (ping), which is the extra trip to a game server and back on top of all this.
See it in action
- BonusWhy does a game judder when it can't keep up?A screen is a flip book with a thumb that turns the page on a steady beat, and the game is an artist drawing the pages.9 min · interactive
- BonusHow does a game controller talk to a console?Your controller fires tiny paper darts at the console hundreds of times a second, each one a snapshot of every button and stick.8 min · interactive
- 14How can lots of people play the same game together?Share a pretend park with friends in other houses: every move is a message to a shared world on a server.7 min · interactive
Do it for real
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