497:
on the laptop's screen and the HDTV simultaneously and recording both screens with a separate video recorder. When the video of both screens is paused, the difference in time shown on both displays have been interpreted as an estimation for the display lag. Nevertheless, this is almost identical to the use of casual stopwatches on two monitors using a "clone view" monitor setup as it does not care about the missing synchronisation between the composite video signal and the display of the laptop's screen or the display lag of that screen or the detail that the vertical screen refresh of the two monitors is still asynchronous and not linked to each other. Even if V-sync is activated in the driver of the graphics card the video signals of the analog and the digital output will not be synchronized. Therefore, it is impossible to use a single stop watch for display lag measurements, nevertheless if it is created by a timecode or a simple stopwatch application, as it will always cause an error of up to
565:
missing the last frame of the window even by 0.1 ms causes an input to be interpreted a full frame later. Because of this, any amount of lag will affect a human's ability to hit a particular timing window. The severity of this impact is a function of the position and variance of a human's response to a visual cue, the amount of lag introduced, and the size of the timing window. For example, given a very large window of 30 frames, a human would likely have a 99.99% chance of hitting this window. By introducing one frame of lag, the human's ability to hit the 30 frame window would likely remain in the 99.99% range (assuming the human is responding somewhere near the middle of the window). Given a smaller window of say 2 frames, however, the effect of lag becomes much more significant. Assuming the human's response is centered on the 2 frame window and the super-human has a 99.99% chance to hit the window, introducing a full frame of lag causes the success rate to drop all the way to about 50%.
139:
178:
77:
36:
564:
By assuming a
Gaussian human response time to a particular in-game event, it becomes possible to discuss the effect of lag in terms of probabilities. Given a lag-less display, a human has a certain probability to land his/her input within a window of frames. As video games operate on discrete frames,
402:
of the display is usually listed in the monitor's specifications, no manufacturers advertise the display lag of their displays, likely because the trend has been to increase display lag as manufacturers find more ways to process input at the display level before it is shown. Possible culprits are the
496:
Several approaches to measure display lag have been restarted in slightly changed ways but still reintroduced old problems, that have already been solved by the former mentioned SMTT. One such method involves connecting a laptop to an HDTV through a composite connection and run a timecode that shows
484:
revealed that these assumptions have been wrong. Averaging measurements as described above lead to comparable results because they include the same amount of systematic errors. As seen on different monitor reviews the so determined values for the display lag for the very same monitor model differ by
385:
the image and make it seem to be clearer or more detailed than it actually is. This is done by storing several interlaced frames and then applying algorithms to determine areas of motion and stillness, and to either merge interlaced frames for smoothing or extrapolate where pixels are in motion, the
492:
To minimize the effects of asynchronous display outputs (the points of time an image is transferred to each monitor is different or the actual used frequency for each monitor is different) a highly specialized software application called SMTT or a very complex and expensive test environment has to
479:
In the past it was seen as common knowledge that the results of this test were exact as they seemed to be easily reproducible, even when the displays were plugged into different ports and different cards, which suggested that the effect is attributable to the display and not the computer system. An
575:
TV viewers can be affected as well. If a home theater receiver with external speakers is used, then the display lag causes the audio to be heard earlier than the picture is seen. "Early" audio is more jarring than "late" audio. Many home-theater receivers have a manual audio-delay adjustment which
475:
of the displays running the stopwatch software, then subtracting the two times on the displays in the photograph. This method only measures the difference in display lag between two displays and cannot determine the absolute display lag of a single display. CRTs are preferable to use as a control
362:
For modern digital signals, significant computer processing power and memory storage is needed to prepare an input signal for display. For either over-the-air or cable TV, the same analog demodulation techniques are used, but after that, then the signal is converted to digital data, which must be
593:
and other consumer-display devices now offer what is often called a "game mode" in which the extensive preprocessing responsible for additional lag is specifically sacrificed to decrease, but not eliminate, latency. While typically intended for videogame consoles, this feature is also useful for
430:, which are built into most modern monitors. As an example, a display that has a native resolution of 1600x1200 being provided a signal of 640x480 must scale width and height by 2.5x to display the image provided by the computer on the native pixels. In order to do this, while producing as few
450:
Many LCDs also use a technology called "overdrive" which buffers several frames ahead and processes the image to reduce blurring and streaks left by ghosting. The effect is that everything is displayed on the screen several frames after it was transmitted by the video source.
598:
for the same reason. Connection through VGA cable or component should eliminate perceivable input lag on many TVs even if they already have a game mode. Advanced post-processing is non existent on analog connection and the signal traverses without delay.
426:. That is, they have a fixed grid of pixels on the screen that show the image sharpest when running at the native resolution (so nothing has to be scaled full-size which blurs the image). In order to display non-native resolutions, such displays must use
543:, also require exact timing; display lag will create a noticeable offset between the music and the on-screen prompts. Notably, many games of this type include an option that attempts to calibrate for display lag. Arguably, fighting games such as
572:'s speaker, etc.), then the display lag will cause this feedback to not accurately match up with the visuals on-screen, possibly causing extra disorientation (e.g. feeling the controller rumble a split second before a crash into a wall).
389:
De-interlacing imposes a delay that can be no shorter than the number of frames being stored for reference, plus an additional variable period for calculating the resulting extrapolated frame buffer; delays of 16-32ms are common.
623:). But an LCD screen with both high response time and significant display lag is unsuitable for playing fast-paced computer games or performing fast high-accuracy operations on the screen, due to the mouse cursor lagging behind.
446:
mode. External devices have also been shown to reduce overall latency by providing faster image-space resizing algorithms than those present in the LCD screen. In practice this would stack the internal and external latencies.
355:, and for the timing of the vertical and horizontal sync. Image adjustments typically involve reshaping the signal waveform but without storage, so the image is written to the screen as fast as it is received, with only
459:
Display lag can be measured using a test device such as the Video Signal Input Lag Tester. Despite its name, the device cannot independently measure input lag. It can only measure input lag and response time together.
343:(CRT) technology, display lag is nearly zero, due to the nature of the technology, which does not have the ability to store image data before display. The picture signal is minimally processed internally, simply for
331:, which is the amount of time it takes for a pixel to change from one brightness value to another. Currently the majority of manufacturers quote the pixel response time, but neglect to report display lag.
509:
Display lag contributes to the overall latency in the interface chain of the user's inputs (mouse, keyboard, etc.) to the graphics card to the monitor. Depending on the monitor, display lag times between
607:
A television may have a picture mode that reduces display lag for computers. Some
Samsung and LG televisions automatically reduce lag for a specific input port if the user renames the port to "PC".
419: – and the cause may vary depending on the model of display. Investigations have been performed by several technology-related websites, some of which are listed at the bottom of this article.
374:
display modes, the signal processing stops here, and the frame buffer is immediately written to the display device. In its simplest form, this processing may take several microseconds to occur.
476:
display because their display lag is typically negligible. However, video mirroring does not guarantee that the same image will be sent to each display at the same point in time.
861:
652:
773:
561:
are the most-affected, since they may require move inputs within extremely tight event windows that sometimes only last 1 frame or 16.67 ms on the screen.
517:
Display lag is most noticeable in games (especially older video-game consoles), with different games affecting the perception of delay. For instance, in
442:
step that adds lag. Anecdotally, display lag is significantly less when displays operate in native resolutions for a given LCD screen and in a
463:
Lacking a measurement device, measurement can be performed using a test display (the display being measured), a control display (usually a
893:
471:
software, and a high-speed camera pointed at the two displays running the stopwatch program. The lag time is measured by taking a
842:
SMTT - Highly optimized display lag test software to reduce the error margin that is usual for plain stopwatch applications
619:
value often do not give satisfactory experience when viewing fast-moving images (they often leave streaks or blur; called
242:
852:
214:
279:
261:
120:
63:
102:
926:
319:
is sent to the display and when the display starts to show that signal. This lag time has been measured as high as
221:
467:) that would ideally have negligible display lag, a computer capable of mirroring an output to the two displays,
777:
696:
514:
have been measured. However, the effects of the delay on the user depend on each user's own sensitivity to it.
199:
87:
846:
228:
902:(July 21, 2006) (Note: this article is compiled from IGN reader opinions and not guaranteed to be accurate)
195:
49:
921:
759:
210:
304:
148:
17:
524:
412:
408:
594:
other interactive applications. Similar options have long been available on home audio hardware and
831:
434:
as possible, advanced signal processing is required, which can be a source of introduced latency.
551:
188:
98:
799:
300:
416:
308:
528:
359:
of delay for the signal to traverse the wiring inside the device from input to the screen.
316:
8:
867:
616:
399:
351:(for televisions), and then splitting into separate signals for the red, green, and blue
328:
235:
155:
Please help update this article to reflect recent events or newly available information.
878:
836:
519:
423:
312:
94:
837:
Input Lag
Testing - Article on TFT Central comparing different methods (14 Dec 2011)
826:
464:
443:
435:
431:
378:
371:
340:
55:
899:
363:
decompressed using the MPEG codec, and rendered into an image bitmap stored in a
832:
Article on PRAD.de - first scientific approach to determine display lag (German)
721:
841:
545:
533:
872:
915:
439:
672:
884:
827:
Database with measurements from input lag for over 200 televisions (German)
590:
427:
364:
352:
348:
344:
745:
620:
539:
386:
resulting calculated frame buffer is then written to the display device.
382:
356:
569:
472:
296:
905:
632:
468:
177:
105:. Statements consisting only of original research should be removed.
568:
If the game's controller produces additional feedback (rumble, the
557:
480:
in depth analysis that has been released on the German website
303:(LCDs) like smartphones and computers and nearly all types of
595:
404:
760:"Untersuchung des Testverfahrens einer Input-Lag-Messung"
324:
527:, a slight input delay is not as critical compared to
653:"Face to Face cameras, printers, ... - DigitalVersus"
481:
862:
BeHardware tests 22inch TFT monitors for display lag
610:
422:LCD, plasma, and DLP displays, unlike CRTs, have a
202:. Unsourced material may be challenged and removed.
504:
531:, or to other games favoring quick reflexes like
381:, additional processing is frequently applied to
151:may be compromised due to out-of-date information
913:
855:LCDs images delayed compared to CRTs? Yes !
327:display. Display lag is not to be confused with
791:
334:
576:can be set to compensate for display latency.
894:Video demonstrating display lag in Windows UI
415:techniques employed to reduce the effects of
323:or the equivalent of 3-4 frames on a 60
27:Phenomenon associated with some types of LCDs
847:FlatpanelsHD.com - Display lag test software
697:"The Dark Side of Overdrive | bit-tech.net"
64:Learn how and when to remove these messages
774:"Melee It on Me | Ugh, This TV Lags!"
454:
879:Video demonstrating display lag in UT2003
438:signals such as 480i and 1080i require a
280:Learn how and when to remove this message
262:Learn how and when to remove this message
121:Learn how and when to remove this message
873:Video demonstrating display lag in Quake
797:
722:"smtt.thomasthiemann.com - SMTT Website"
719:
673:"HCI Design: Monitor Input Lag database"
393:
14:
914:
800:"How to use your 4K TV as a monitor"
200:adding citations to reliable sources
171:
132:
70:
29:
24:
25:
938:
906:Anandtech article about Input Lag
820:
798:Morrison, Geoffrey (2015-07-21).
602:
45:This article has multiple issues.
868:Avs Forum posting on display lag
611:Display lag versus response time
176:
137:
75:
34:
720:Thiemann, Thomas (2020-05-22).
505:Effects of display lag on users
187:needs additional citations for
53:or discuss these issues on the
766:
752:
738:
713:
689:
665:
645:
537:. Rhythm-based games, such as
299:associated with most types of
13:
1:
638:
887:Display lag and TFT features
584:
579:
347:from a radio-frequency (RF)
335:Analog vs digital technology
7:
626:
305:high-definition televisions
101:the claims made and adding
10:
943:
900:The HDTV-Gaming-Lag Report
409:digital rights management
615:LCD screens with a high
927:Liquid crystal displays
746:"Google Sites: Sign-in"
552:Super Smash Bros. Melee
455:Testing for display lag
403:processing overhead of
301:liquid crystal displays
307:(HDTVs). It refers to
394:Causes of display lag
444:progressive scanning
196:improve this article
400:pixel response time
329:pixel response time
922:Display technology
853:BeHardware test -
589:Many televisions,
86:possibly contains
762:. 27 August 2009.
520:World of Warcraft
424:native resolution
339:For older analog
315:between when the
290:
289:
282:
272:
271:
264:
246:
170:
169:
131:
130:
123:
88:original research
68:
16:(Redirected from
934:
814:
813:
811:
810:
795:
789:
788:
786:
785:
776:. Archived from
770:
764:
763:
756:
750:
749:
742:
736:
735:
733:
732:
717:
711:
710:
708:
707:
693:
687:
686:
684:
683:
669:
663:
662:
660:
659:
649:
513:
500:
488:
436:Interlaced video
411:(DRM), and also
379:interlaced video
372:progressive scan
341:cathode ray tube
322:
285:
278:
267:
260:
256:
253:
247:
245:
204:
180:
172:
165:
162:
156:
149:factual accuracy
141:
140:
133:
126:
119:
115:
112:
106:
103:inline citations
79:
78:
71:
60:
38:
37:
30:
21:
942:
941:
937:
936:
935:
933:
932:
931:
912:
911:
908:(July 16, 2009)
881:(June 27, 2006)
875:(June 24, 2006)
823:
818:
817:
808:
806:
796:
792:
783:
781:
772:
771:
767:
758:
757:
753:
744:
743:
739:
730:
728:
726:Thomas Thiemann
718:
714:
705:
703:
695:
694:
690:
681:
679:
671:
670:
666:
657:
655:
651:
650:
646:
641:
629:
613:
605:
587:
582:
511:
507:
498:
486:
457:
396:
337:
320:
286:
275:
274:
273:
268:
257:
251:
248:
205:
203:
193:
181:
166:
160:
157:
154:
146:This article's
142:
138:
127:
116:
110:
107:
92:
80:
76:
39:
35:
28:
23:
22:
15:
12:
11:
5:
940:
930:
929:
924:
910:
909:
903:
897:
896:(Dec 12, 2006)
891:
890:(Oct 29, 2008)
885:TFT Central -
882:
876:
870:
865:
864:(Dec 19, 2006)
859:
850:
849:(Dec 15, 2008)
844:
839:
834:
829:
822:
821:External links
819:
816:
815:
790:
765:
751:
737:
712:
688:
664:
643:
642:
640:
637:
636:
635:
628:
625:
612:
609:
604:
603:Renaming input
601:
586:
583:
581:
578:
546:Street Fighter
534:Counter-Strike
506:
503:
501:or even more.
489:or even more.
485:margins up to
456:
453:
395:
392:
336:
333:
288:
287:
270:
269:
184:
182:
175:
168:
167:
145:
143:
136:
129:
128:
83:
81:
74:
69:
43:
42:
40:
33:
26:
9:
6:
4:
3:
2:
939:
928:
925:
923:
920:
919:
917:
907:
904:
901:
898:
895:
892:
889:
888:
883:
880:
877:
874:
871:
869:
866:
863:
860:
858:(Aug 3, 2006)
857:
856:
851:
848:
845:
843:
840:
838:
835:
833:
830:
828:
825:
824:
805:
801:
794:
780:on 2015-02-20
779:
775:
769:
761:
755:
747:
741:
727:
723:
716:
702:
698:
692:
678:
677:hcidesign.com
674:
668:
654:
648:
644:
634:
631:
630:
624:
622:
618:
617:response-time
608:
600:
597:
592:
577:
573:
571:
566:
562:
560:
559:
554:
553:
548:
547:
542:
541:
536:
535:
530:
526:
523:
521:
515:
502:
494:
490:
483:
477:
474:
470:
466:
461:
452:
448:
445:
441:
440:deinterlacing
437:
433:
429:
428:video scalers
425:
420:
418:
414:
410:
406:
401:
391:
387:
384:
380:
375:
373:
368:
366:
360:
358:
354:
353:electron guns
350:
346:
342:
332:
330:
326:
318:
314:
310:
306:
302:
298:
294:
284:
281:
266:
263:
255:
244:
241:
237:
234:
230:
227:
223:
220:
216:
213: –
212:
211:"Display lag"
208:
207:Find sources:
201:
197:
191:
190:
185:This article
183:
179:
174:
173:
164:
161:November 2010
152:
150:
144:
135:
134:
125:
122:
114:
111:February 2012
104:
100:
96:
90:
89:
84:This article
82:
73:
72:
67:
65:
58:
57:
52:
51:
46:
41:
32:
31:
19:
886:
854:
807:. Retrieved
803:
793:
782:. Retrieved
778:the original
768:
754:
740:
729:. Retrieved
725:
715:
704:. Retrieved
701:bit-tech.net
700:
691:
680:. Retrieved
676:
667:
656:. Retrieved
647:
614:
606:
588:
574:
567:
563:
556:
550:
544:
538:
532:
518:
516:
508:
495:
491:
478:
462:
458:
449:
421:
397:
388:
376:
369:
365:frame buffer
361:
349:carrier wave
345:demodulation
338:
292:
291:
276:
258:
252:January 2012
249:
239:
232:
225:
218:
206:
194:Please help
189:verification
186:
158:
147:
117:
108:
85:
61:
54:
48:
47:Please help
44:
540:Guitar Hero
383:deinterlace
357:nanoseconds
293:Display lag
916:Categories
809:2020-01-31
784:2015-02-22
731:2022-05-03
706:2024-09-06
682:2022-05-03
658:2008-03-07
639:References
570:Wii Remote
473:photograph
398:While the
297:phenomenon
222:newspapers
95:improve it
50:improve it
18:Output lag
633:Input lag
585:Game mode
580:Solutions
493:be used.
469:stopwatch
432:artifacts
99:verifying
56:talk page
627:See also
621:ghosting
512:10-68 ms
417:ghosting
591:scalers
482:Prad.de
309:latency
236:scholar
93:Please
596:modems
558:Tekken
321:68 ms,
317:signal
238:
231:
224:
217:
209:
499:16 ms
487:16 ms
311:, or
295:is a
243:JSTOR
229:books
804:CNET
555:and
405:HDCP
377:For
370:For
215:news
529:PvP
525:PvE
465:CRT
413:DSP
313:lag
198:by
97:by
918::
802:.
724:.
699:.
675:.
549:,
522:'s
407:,
367:.
325:Hz
59:.
812:.
787:.
748:.
734:.
709:.
685:.
661:.
283:)
277:(
265:)
259:(
254:)
250:(
240:·
233:·
226:·
219:·
192:.
163:)
159:(
153:.
124:)
118:(
113:)
109:(
91:.
66:)
62:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
