Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Input lag
open-in-new
<h2 id="potential-causes-of-delay-from-pressing-a-button-to-the-game-reacting">Potential causes of delay from pressing a button to the game reacting</h2> <p>The potential causes for input lag are described below. Each step in the process, however small, increases total input lag, however the combined result may not be noticeable if all input lag is low enough. </p> <h3>Controller sends signal to console</h3> <p>For wired controllers, this lag is normally negligible. For wireless controllers, opinions vary as to the significance of this lag. Some people claim to notice extra lag when using a wireless controller, while other people claim that the 4–8 milliseconds of lag is negligible.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a> </p> <h3>Console/PC processes next frame</h3> <p>A <a href="/facts/Videogame_console/K72D1NSS">videogame console</a> or <a href="/facts/Personal_computer/koaYfNce">PC</a> will send out a new <a href="/facts/Film_frame/27Uqo8WN">frame</a> once it has finished performing the necessary calculations to create it. The amount of frames rendered per <a href="/facts/Second/jtFxnJXx">second</a> (on <a href="/facts/Average/etawWjw4">average</a>) is called the <a href="/facts/Frame_rate/sbRkc9xa">frame rate</a>. Using common a 60 <a href="/facts/Hertz/6Wshj5qm">Hz</a> monitor as an example, the maximum theoretical frame rate is 60 <a href="/facts/Frames_per_second/sbRkc9xa">FPS</a> (frames per second), which means the minimum theoretical input lag for the overall system is approximately 16.67 ms (1 frame/60 FPS). The monitor is usually the <a href="/facts/Bottleneck_(engineering)/v5gbkUqG">bottleneck</a> for the theoretical maximum FPS, since there is little point in rendering more frames than the monitor can show. In situations where the <a href="/facts/Central_processing_unit/Jxp1bqMV">CPU</a>, <a href="/facts/Graphics_processing_unit/PTK1RQVp">GPU</a>, <a href="/facts/Random-access_memory/DuD4bxh6">memory</a>, <a href="/facts/Bus_(computing)/R45TKwS7">bus</a>, etc. load is bottlenecked, FPS can drop below the monitor's refresh rate. </p><p>Individual frames need not be finished within the interval of a screen refresh to output at an equivalent rate. <a href="/facts/Game_engine/lojx7lTG">Game engines</a> often make use of <a href="/facts/Pipeline_(computing)/xmHjrPMP">pipelined</a> architectures to process multiple frames <a href="/facts/Parallel_computing/nQzcpzQt">concurrently</a>, allowing for a more efficient use of the underlying <a href="/facts/Computer_hardware/8jSjsCNv">hardware</a>. This exacerbates input lag, especially at low frame rates.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a><a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> </p> <h3>Display lag</h3> <p class="note">Main article: <a href="/facts/Display_lag/L53RTLrv">Display lag</a></p> <p>This is the lag caused by the television or monitor (also called output lag). In addition to the latency imposed by the screen's <a href="/facts/Pixel_response_time/3kQrmztQ">pixel response time</a>, any image processing (such as <a href="/facts/Image_scaling/qNoeujzm">upscaling</a>, <a href="/facts/Motion_interpolation/9xFAqRSn">motion smoothing</a>, or <a href="/facts/Spatial_anti-aliasing/od0SgvLy">edge smoothing</a>) takes time and therefore adds more input lag. An input lag below 30 <a href="/facts/Millisecond/xHCyv235">ms</a> is generally considered unnoticeable in a <a href="/facts/Television_screen/8moTsqhB">television</a>.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> Once the frame has been processed, the final step is the updating the <a href="/facts/Pixel/UzwBvXBV">pixels</a> to display the correct color for the new frame. The time this takes is called the <a href="/facts/Pixel_response_time/3kQrmztQ">pixel response time</a>. </p> <h2 id="typical-overall-response-times">Typical overall response times</h2> <p>Testing has found that overall input lag (from human input to visible response) times of approximately 200 ms are distracting to the user. It also appears that (excluding the monitor/television display lag) 133 ms is an average response time and the most sensitive games (<a href="/facts/Fighting_games/7Y7FaQTK">fighting games</a>, <a href="/facts/First_person_shooters/LQQX6yAw">first person shooters</a> and <a href="/facts/Rhythm_games/BrtxkpAL">rhythm games</a>) achieve response times of 67 ms (excluding display lag).<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Response_time_(technology)/3kQrmztQ">Response time (technology)</a></li></ul> <h2 id="external-links">External links</h2> <ul><li><a href="https://www.dein-fernseher.de/input-lag-fernseher/">Input Lag Test: TVs from 2016 + 2017</a> Dein-Fernseher.de</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"Wireless Controller Latency: is It a Problem? - LockerGnome". LockerGnome. 2011-08-27. Archived from the original on 2016-08-28. Retrieved 2016-06-12. <a href="https://web.archive.org/web/20160828170616/http://www.lockergnome.com/uncategorized/2011/08/26/wireless-controller-latency-is-it-a-problem/" target="_blank">https://web.archive.org/web/20160828170616/http://www.lockergnome.com/uncategorized/2011/08/26/wireless-controller-latency-is-it-a-problem/</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Ericson, Christer (2007-09-22). "Input latency". realtimecollisiondetection.net - the blog. <a href="https://realtimecollisiondetection.net/blog/?p=30" target="_blank">https://realtimecollisiondetection.net/blog/?p=30</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Carmack, John (2013-02-22). "Latency Mitigation Strategies". #AltDevBlogADay. Archived from the original on 2013-02-25. <a href="https://danluu.com/latency-mitigation/" target="_blank">https://danluu.com/latency-mitigation/</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>"The Dark Side of Overdrive". bit-tech. Retrieved 2016-06-12. <a href="http://www.bit-tech.net/hardware/monitors/2009/02/06/the-dark-side-of-overdrive/4" target="_blank">http://www.bit-tech.net/hardware/monitors/2009/02/06/the-dark-side-of-overdrive/4</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>"Console Gaming: The Lag Factor". Eurogamer. Gamer Network. 5 September 2009. p. 2. Retrieved 2016-06-12. <a href="http://www.eurogamer.net/articles/digitalfoundry-lag-factor-article?page=2" target="_blank">http://www.eurogamer.net/articles/digitalfoundry-lag-factor-article?page=2</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> </ol>