lcd panel input lag supplier

Don’t fall for this trap from display manufacturers when buying a display. Display manufacturers DO NOT advertise a display’s input lag when you’re buying a display, either on the box, on the manual, or anywhere relevant to their interests. I’m sure there are valid reasons for this, but due to the nature of the phrase “response time”, a lot of people get confused into thinking it reflects a display’s input lag. It does not.

In a way, yes. As a pixel is inactive when it’s black, and active when it’s white, it means that a picture needs to be visible before you can react to what’s on the screen. The faster the response time of a display is, the quicker it can display an image. The quicker it does that, the quicker you can react to it. This is the reason why the lag tester is such a valuable tool; it records the combined display response time and input lag of the HDTV or monitor, and displays it as a single number. It’s a new way to measure this phenomenon that makes more sense. With a combined measurement for both response time and input lag, gamers can rest assured that a display is fast enough to reduce image ghosting, and responsive enough to register their inputs as soon as possible.

In summation, don’t read too deeply into the response time rating advertised by display manufacturers. I’m glad manufacturers advertise it, as long as it’s not confused with input lag, which is NOT advertised. Want to know the combined response time and input lag of a specific display? Head over to the

Display lag is a phenomenon associated with most types of liquid crystal displays (LCDs) like smartphones and computers and nearly all types of high-definition televisions (HDTVs). It refers to latency, or lag between when the signal is sent to the display and when the display starts to show that signal. This lag time has been measured as high as 68 ms,Hz display. Display lag is not to be confused with pixel response time, 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.

For older analog cathode ray tube (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 demodulation from a radio-frequency (RF) carrier wave (for televisions), and then splitting into separate signals for the red, green, and blue electron guns, 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 nanoseconds of delay for the signal to traverse the wiring inside the device from input to the screen.

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 decompressed using the MPEG codec, and rendered into an image bitmap stored in a frame buffer.

While the pixel response time 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 processing overhead of HDCP, Digital Rights Management (DRM), and also DSP techniques employed to reduce the effects of ghosting – 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.

LCD, plasma, and DLP displays, unlike CRTs, have a native resolution. 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 video scalers, 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 artifacts as possible, advanced signal processing is required, which can be a source of introduced latency. Interlaced video signals such as 480i and 1080i require a deinterlacing step that adds lag. Anecdotallyprogressive scanning 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.

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.

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.

Lacking a measurement device, measurement can be performed using a test display (the display being measured), a control display (usually a CRT) that would ideally have negligible display lag, a computer capable of mirroring an output to the two displays, stopwatch software, and a high-speed camera pointed at the two displays running the stopwatch program. The lag time is measured by taking a photograph 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 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.

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 in depth analysis that has been released on the German website Prad.de 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 margins up to 16 ms or even more.

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 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.16 ms or even more.

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 10-68 ms have been measured. However, the effects of the delay on the user depend on each user"s own sensitivity to it.

Display lag is most noticeable in games (especially older video-game consoles), with different games affecting the perception of delay. For instance, in PvE, a slight input delay is not as critical compared to PvP, or to other games favoring quick reflexes like

If the game"s controller produces additional feedback (rumble, the Wii Remote"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).

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 can be set to compensate for display latency.

Many televisions, scalers 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 other interactive applications. Similar options have long been available on home audio hardware and modems 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.

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".

LCD screens with a high response-time value often do not give satisfactory experience when viewing fast-moving images (they often leave streaks or blur; called ghosting). 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.

One of the areas where the A-MVA panel does extremely well is in the areas of display lag and pixel response time. Just to recap, you may have heard complaints about "input lag" on various LCDs, so that"s one area we look at in our LCD reviews. We put input lag in quotation marks because while many people call it "input lag", the reality is that this lag occurs somewhere within the LCD panel circuitry, or perhaps even at the level of the liquid crystals. Where this lag occurs isn"t the concern; instead, we just want to measure the duration of the lag. That"s why we prefer to call it "processing lag" or "display lag".

To test for display lag, we run the Wings of Fury benchmark in 3DMark03, with the output set to the native LCD resolution - in this case 1920x1200. Our test system is a quad-core Q6600 running a Radeon HD 3870 on a Gigabyte GA-X38-DQ6 motherboard - we had to disable CrossFire support in order to output the content to both displays. We connect the test LCD and a reference LCD to two outputs from the Radeon 3870 and set the monitors to run in clone mode.

The reference Monitor is an HP LP3065, which we have found to be one of the best LCDs we currently possess in terms of not having display lag. (The lack of a built-in scaler probably has something to do with this.) While we know some of you would like us to compare performance to a CRT, that"s not something we have around our offices anymore. Instead, we are looking at relative performance, and it"s possible that the HP LP3065 has 20ms of lag compared to a good CRT - or maybe not. Either way, the relative lag is constant, so even if a CRT is faster at updating, we can at least see if an LCD is equal to or better than our reference display.

While the benchmark is looping, we snap a bunch of pictures of the two LCDs sitting side-by-side (using a relatively fast shutter speed). 3DMark03 shows the runtime with a resolution of 10ms at the bottom of the display, and we can use this to estimate whether a particular LCD has more or less processing lag than our reference LCD. We sort through the images and discard any where the times shown on the LCDs are not clearly legible, until we are left with 10 images for each test LCD. We record the difference in time relative to the HP LP3065 and average the 10 results to come up with an estimated processing lag value, with lower numbers being better. Negative numbers indicate a display is faster than the HP LP3065, while positive numbers mean the HP is faster and has less lag.

It"s important to note that this is merely an estimate - whatever the reference monitor happens to be, there are some inherent limitations. For one, LCDs only refresh their display 60 times per second, so we cannot specifically measure anything less than approximately 17ms with 100% accuracy. Second, the two LCDs can have mismatched vertical synchronizations, so it"s entirely possible to end up with a one frame difference on the time readout because of this. That"s why we average the results of 10 images, and we are confident that our test procedure can at least show when there is a consistent lag/internal processing delay. Here is a summary of our results for the displays we have tested so far.

As you can see, all of the S-PVA panels we have tested to date show a significant amount of input lag, ranging from 20ms up to 40ms. In contrast, the TN and S-IPS panels show little to no processing lag (relative to the HP LP3065). The BenQ FP241VW performs similarly to the TN and IPS panels, with an average display lag of 2ms - not something you would actually notice compared to other LCDs. Obviously, if you"re concerned with display lag at all, you"ll want to avoid S-PVA panels for the time being. That"s unfortunate, considering S-PVA panels perform very well in other areas.

Despite what the manufacturers might advertise as their average pixel response time, we found most of the LCDs are basically equal in this area - they all show roughly a one frame "lag", which equates to a response time of around 16ms. In our experience, processing lag is far more of a concern than pixel response times. Taking a closer look at just the FP241VW, we can see the typical one frame lag in terms of pixel response time. However, the panel does appear to be a little faster in response time than some of the other panels we"ve tested (notice how the "ghost image" isn"t as visible as on the HP LP3065), and we didn"t see parts of three frames in any of the test images.

After the initial article went live, one of our readers who works in the display industry sent me an email. He provides some interesting information about the causes of image lag. Below is an (edited) excerpt from his email. (He wished to remain anonymous.)

PVA and MVA have inherent drawbacks with respect to LCD response time, especially gray-to-gray. To address this shortcoming, companies have invested in ASICs that perform a trick generically referred to as "overshoot." The liquid crystal (LC) material in *VA responds sluggishly to small voltage changes (a change from one gray level to another). To fix this, the ASIC does some image processing and basically applies an overvoltage to the electrodes of the affected pixel to spur the LC material into rapid movement. Eventually the correct settling voltage is applied to hold the pixel at the required level matching the input drive level.

It"s very complicated math taking place in the ASIC in real time. It works well but with an important caveat: it requires a frame buffer. What this means is that as video comes into the panel, there is a memory device that can capture one whole video frame and hold it. After comparing it to the next incoming frame, the required overshoot calculations are made. Only then is the first captured frame released to the panel"s timing controller, which is when the frame is rendered to the screen. As you may have already guessed, that causes at least one frame time worth of lag (17ms).

Some companies discovered some unintended artifacts in their overshoot calculations and the only way they saw to correct these was to allow for their algorithm to look ahead by two frames instead of one. So they had to up the memory of the frame buffer and now they started capturing and holding not one but two frames upon which they make their complex overshoot predictions to apply the corrected pixel drive levels and reduce gray-to-gray response time (at the expense of lag time). Again, it works very well for improving response time, but at the expense of causing lag, which gamers hate. That in a nutshell is the basis of around 33ms of the lag measured with S-PVA.

Not every display uses this approach, but this could account for the increase in display lag between earlier S-PVA and later S-PVA panels. It"s also important to note that I tested the Dell 2408WFP revision A00, and apparently revision A01 does not have as much lag. I have not been able to confirm this personally, however. The above also suggest that displays designed to provide a higher image quality through various signal processing techniques could end up with more display lag caused by the microchip and microcode, which makes sense. Now all we need are better algorithms and technologies in order to reduce the need for all of this extra image processing -- or as we have seen with some displays (particularly HDTVs), the ability to disable the image processing.

A high level of input lag can greatly impact your overall gaming experience and especially in twitch-sensitive games. We’d consider anything under 20ms as good for gaming. Options, as high as 68ms, may completely cripple your overall gaming experience. Monitors with high refresh rates that are made for gaming typically fall into this category as the time for each frame to remain on the screen is greatly diminished.  However, there are many cheap gaming monitors available with extremely low latency.

Modern TVs and monitors are often plagued more than previous generation CRT versions as additional processing power and memory storage is is necessary in order to display a command. So most of what is determined as display lag is built-in to your device. However, if you’ve already purchased your TV or monitor, there are some ways to decrease its overall input lag.

Testing for input lag has a lot of processes involved with it. The most rudimentary method we’ve seen of doing this involves recording your display and input at the same time and then trying to calculate the difference in time. There are other better ways of doing this including devices made specifically for this type of testing. These include the Video Signal Input Lag Tester from Leo Bodnar Electronics. Perhaps a more practical way of doing this is to simply go to a site where display lag is measured. Prad.de is one such site but there are many others as well.

Many people get input lag confused with response time. Response time is the time it takes for a pixel to go from black to white and then back again. Often manufacturers will post their GTG or gray to gray response time in order to achieve a lower number. Monitors that have a below 5ms response time typically leave blur with images that move quickly.

Ever wondered whether G-Sync or FreeSync is better or want to know more about them? Linus over at Linus Tech Tips gives us a good comparison to look at. We found this test valuable albeit somewhat unscientific. Different panels will give different results. So, proper testing would involve using a display that is both G-Sync and FreeSync compatible.

Ultimately picking a monitor or HDTV that already comes with a low amount of display lag is the easiest way to make sure you have a smooth gaming experience. If you’ve already bought your monitor or display, try taking some of the steps we mentioned above to remedy the situation.

While both input lag and response time are equally important for a fluid gaming experience, too high input lag can make competitive gaming unbearable.

So, a 120Hz display will have essentially half the input lag in comparison to a 60Hz display since the picture gets updated more frequently and you can react to it sooner.

Pretty much all new high refresh rate gaming monitors have low enough input lag in relation to their refresh rate that the delay between your actions and the result on the screen will be imperceptible.

When you"re using a monitor, you want your actions to appear on the screen almost instantly, whether you"re typing, clicking through websites, or gaming. If you have high input lag, you"ll notice a delay from the time you type something on your keyboard or when you move your mouse to when it appears on the screen, and this can make the monitor almost unusable.

For gamers, low input lag is even more important because it can be the difference between winning and losing in games. A monitor"s input lag isn"t the only factor in the total amount of input lag because there"s also delay caused by your keyboard/mouse, PC, and internet connection. However, having a monitor with low input lag is one of the first steps in ensuring you get a responsive gaming experience.

Any monitor adds at least a few milliseconds of input lag, but most of the time, it"s small enough that you won"t notice it at all. There are some cases where the input lag increases so much to the point where it becomes noticeable, but that"s very rare and may not necessarily only be caused by the monitor. Your peripherals, like keyboards and mice, add more latency than the monitor, so if you notice any delay, it"s likely because of those and not your screen.

There"s no definitive amount of input lag when people will start noticing it because everyone is different. A good estimate of around 30 ms is when it starts to become noticeable, but even a delay of 20 ms can be problematic for reaction-based games. You can try this tool that adds lag to simulate the difference between high and low input lag. You can use it to estimate how much input lag bothers you, but keep in mind this tool is relative and adds lag to the latency you already have.

There are three main reasons why there"s input lag during computer use, and it isn"t just the monitor that has input lag. There"s the acquisition of the image, the processing, and finally actually displaying it.

The acquisition of the image has to do with the source and not with the monitor. The more time it takes for the monitor to receive the source image, the more input lag there"ll be. This has never really been an issue with PCs since previous analog signals were virtually instant, and current digital interfaces like DisplayPort and HDMI have next to no inherent latency. However, some devices like wireless mice or keyboards may add delay. Bluetooth connections especially add latency, so if you want the lowest latency possible in the video acquisition phase, you should use a wired mouse or keyboard or get something wireless with very low latency.

The time this step takes is affected by the speed of the video processor and the total amount of processing. Although you can"t control the processor speed, you can control how many operations it needs to do by enabling and disabling settings. Most picture settings won"t affect the input lag, and monitors rarely have any image processing, which is why the input lag on monitors tends to be lower than on TVs. One of these settings that could add delay is variable refresh rate, but most modern monitors are good enough that the lag doesn"t increase much.

Once the monitor has processed the image, it"s ready to be displayed on the screen. This is the step where the video processor sends the image to the screen. The screen can"t change its state instantly, and there"s a slight delay from when the image is done processing to when it appears on screen. Our input lag measurements consider when the image first appears on the screen and not the time it takes for the image to fully appear (which has to do with our Response Time measurements). Overall, the time it takes to display the image has a big impact on the total input lag.

It"s also worth considering your own eyesight and desktop setup. If you have 20/20 vision and your eyes are around 20” from your screen, a 27” 4K panel will provide an immediate visual upgrade. However, if you know your eyesight is worse than 20/20, or you prefer to sit more than 24” away, a 1440p panel may look just as good to you.

Use caution when LCDs advertise very high “dynamic contrast ratios”, which are achieved by changing the behavior of the backlight. For gaming or everyday use, the standard “static” contrast ratio discussed above is a better marker of the monitor"s quality.

Black LevelIn all LCD screens, light from the backlight inevitably leaks through the liquid crystal. This provides the basis for the contrast ratio: For example, if the screen leaks 0.1% of the illumination from the backlight in an area that"s supposed to be black, this establishes a contrast ratio of 1,000:1. An LCD screen with zero light leakage would have an infinite contrast ratio. However, this isn"t possible with current LCD technology.

“Glow” is a particular issue in dark viewing environments, which means that achieving low black levels is a major selling point for LCD monitors. However, an LCD screen can’t reach a black level of 0 nits unless it’s completely turned off.

Some inexpensive LCD panels use 6-bit color along with “dithering” to approximate 8-bit color. In this context, dithering means the insertion of similar, alternating colors next to one another to fool the eye into seeing a different in-between color that the monitor cannot accurately display.

Monitors sometimes feature a Look-Up Table (LUT) corresponding to a higher color depth, such as 10-bit color. This helps speed up color correction calculations that take place within the monitor as it converts color input to a color output appropriate for your screen. This intermediate step can help create smoother color transitions and more accurate output. These are usually reserved for more professional grade monitors than general consumer and gaming displays.

In LCD screens, the backlight and color filters determine the color space. All of the light created by the backlight passes through a color filter with red, green, and blue spots. Narrowing the “band-pass” of this filter restricts the wavelengths of light that can pass through, increasing the purity of the final colors produced. Although this lessens the screen"s efficiency (as the filter now blocks more of the backlight"s output), it creates a wider color gamut.

Though they work best with HDR content (which only some games and movies support), these monitors typically support 10-bit color depth and backlights that support a wide color gamut, which will also improve standard content (SDR). (Note that HDR monitors are often not true 10-bit color, but rather 8+2FRC displays that accept a 10-bit input signal).

For LCD displays, a high-end backlight feature called local dimming is critical to HDR quality. Dimming zones for the backlight behind the screen control the brightness of groups of LEDs; more dimming zones means more precise control, less “blooming” (where light areas of the image brighten dark ones), and generally improved contrast.

Full Array Local Dimming (FALD), a more high-end option, uses far more dimming zones (typically hundreds) directly behind the panel rather than just at the edges of the screen. It can give more finite control of the HDR content and dimming of the screen as a result.

Players sometimes confuse response time with input lag, a measurement of the delay before your actions appear onscreen, similarly measured in milliseconds. Input lag is felt rather than seen, and is often a priority for players of fighting games and first-person shooters.

Input lag is a side effect of the processing done by the monitor scaler and the screen"s internal electronics. Selecting “Game Mode” on your monitor"s adjustment menu often switches off image processing features and lessens input lag. Disabling VSync (which prevents some visual artifacts) in in-game option menus can also help reduce input lag.

VSync (vertical sync) provides one solution to this issue. This in-game feature reduces the speed at which frames are drawn in order to match your monitor"s refresh rate. However, VSync can cause stuttering when the frame rate drops below that cap. (For example, the GPU may suddenly drop to 30fps when it can"t deliver 60fps). The increased load on the GPU can also result in input lag.

G-Sync monitors use NVIDIA"s proprietary G-Sync scaler chip to match monitor refresh rates to GPU output, as well as predict GPU output based on recent performance. It also helps prevent stutter and input lag, which can result from duplicate frames being drawn as the first one waits to be displayed.

Both LCDs and OLEDs "sample and hold", displaying moving objects as a series of static images that are rapidly refreshed. Each sample remains onscreen until it"s replaced with the next refresh. This "persistence" causes motion blur, as the human eye expects to track objects smoothly rather than see them jump to a new position. Even at high refresh rates, which update the image more often, the underlying sample-and-hold technology causes motion blur.

This mimics the operation of older CRT monitors, which worked differently than current LCD technology. CRT screens were illuminated by phosphors that rapidly decayed, providing brief impulses of illumination. This meant that the screen was actually dark for most of the refresh cycle. These quick impulses actually created a smoother impression of motion than sample-and-hold, and motion blur reduction features work to replicate this effect.

Cathode Ray Tube (CRT)These boxy computer monitors were common from the 1970s until the early 2000s, and are still prized by some players today for their low input lag and response times.

Liquid Crystal Display (LCD)In TFT LCDs (thin-film-transistor liquid crystal displays), a backlight shines light through a layer of liquid crystals that can twist, turn, or block it. The liquid crystals do not emit light themselves, which is a key difference between LCDs and OLEDs.

Older LCDs used Cold-Cathode Fluorescent Lamps (CCFLs) as backlights. These large, energy-inefficient tubes were incapable of controlling the brightness of smaller zones of the screen, and were eventually phased out in favor of smaller, energy-efficient light-emitting diodes (LEDs).

LCD panels are available in a range of technologies and can vary widely in color reproduction, response time, and input lag, especially among high-end options. However, the following generalizations about panels usually hold true:

Oldest and most affordable LCD panel type. High refresh rates and response times for high-speed gaming such as first-person shooters or fighting games.

Vertically aligned liquid crystals line up with two polarizers, rather than twisting, as in a TN panel. When in a resting state, the crystals can more effectively block illumination than TN panels.

Often slow response times, particularly on black-to-gray color transitions, often resulting in “black smearing” in motion. Wider viewing angles than TN panels, but often less than IPS panels. Some VA panels suffer significant color shift when viewed off-axis.

Widest viewing angles. Most stable image quality. Deeper blacks and better contrast ratios than TN panels. Most are 6-bit+2, but 8-bit and 8+2 panels exist. Often highly rated premium panels.

Pale glow, known as “IPS glow” visible when viewing screens in dark rooms from off-center angles. Response times usually worse than TN panels, but better than VA panels. Lower contrast ratio than VA panels.

Organic Light-Emitting Diode (OLED)OLED screens are emissive, meaning they create their own light, rather than transmissive screens that require a separate light source (like LCDs). Here, the application of electric current causes a layer of organic molecules to light up on the front of the screen.

Backlights may be imperfectly blocked by the liquid crystals in an LCD, causing black areas of an image to appear gray. Because OLEDs have no backlight, they can achieve “true black” by simply turning off a pixel (or at least 0.0005 nits, the lowest measurable brightness).

OLEDs therefore boast very high contrast ratios and vibrant color. The elimination of the backlight also makes them slimmer than LCDs. Much as LCDs were a thinner, more energy-efficient evolution of CRTs, OLEDs may prove a thinner evolution of LCDs. (They can also be more energy-efficient when displaying dark content, like movies, but less energy-efficient with white screens, such as word processing programs).

Input: 3.5mm jack for connecting an audio cable from your computer, allowing you to play sound over the monitor"s internal speakers. Note that HDMI and DisplayPort cables also transmit audio, and are a simpler solution for many users.

Figuring out what to look for in a gaming monitor depends heavily on the choices you"ve made about the rest of your computer. Modern monitors can generally help you avoid the dropped frames, input lag, and visual artifacts common in older technologies, but the value of increased resolution, color depth, and motion smoothing features will vary from player to player. It"s down to you to separate the must-haves from the nice-to-haves.

Your monitor’s display settings may increase the delay between inputting commands and seeing the result on your display. Some display parameters are configurable, while others are built into the hardware and cannot be changed.

The first thing to look at is your monitor’s refresh rate. A higher refresh rate increases the number of individual frames that your monitor displays per second. Displaying more frames per second reduces the delay between inputting a command and seeing its result on the screen, shaving valuable milliseconds off input lag.

Not all wired connections provide the same response time benefits. Some displays (especially Smart TVs) add processing effects like visual noise reduction to AV input, which adds to latency. To avoid this, check to see if your TV features a “Game Mode” that minimizes input lag by bypassing video signal processing.

Keep in mind that every TV and monitor has a unique, hardware-defined input latency. This is the amount of time that it takes the display to receive, process, and show incoming data. It is built into the hardware of the screen itself and cannot be changed.

Manufacturers don’t generally advertise their products’ latency delays. Instead, they focus on “response time,” which measures how long it takes for individual pixels to change color. It’s easy to confuse these two, but response time doesn’t have a significant impact on input lag.

Many new, gaming-ready displays have an input latency of 10-15 milliseconds. There are third-party websites that conduct and list monitor input latency scores, so it’s possible to verify how much of your input lag is built in.

Most computer engineers would define a display’s input lag as being the difference in time between the output from a graphics card, to the time that image is displayed on the screen. There are other factors which constitute “lag” which we will discuss on this page, and which ones you should be the most concerned about when looking to purchase a display or device for gaming.

It is worth noting that the display tests measure a different type of lag than the peripheral devices tests, and that the phrase “Input Lag” has no actual defined measurement by computer scientists. Display input lag is concerned with the time required for the pixels to show an image after it has been processed and sent by the graphics card. This is different than the manufacturers quoted pixel responsiveness time (such as GTG response time, or BTW – more on this in a bit), which measures how quickly the pixels can change from one color to another. Pixel response times are what affect things like motion blurring and ghosting – which also an important measure for gamers needing maximum performance for fast paced games.

The amount of lag varies greatly depending on the display, hence why there is a noted difference between manufacturers gaming displays vs their normal ones for casual/business use. It’s become commonplace for manufacturers to focus on gaming displays to provide the fastest response times and lowest input lag possible for the type of panel being used. The difference in lag depends on the internals of a monitor, such as its internal circuit board and scaling chips, which determine its signal processing time and therefore its quoted input lag and responsiveness. Many manufacturers take active measures for their gaming displays to reduce input lag as much as possible, with many offering modes which can bypass the scaling chips and including other options to reduce the input lag.

Short answer:input lag is caused by a combination of two things – the signal processing delay caused by the monitor’s internal electronic board, and the response time of the pixels.

“Input Lag” is made up of 2 parts. When a signal is sent from the GPU to a screen, the instant it hits the port on the back of the monitor/TV it begins what we would define as “Input Lag”. As the signal enters the display, it has 2 sections of lag, which can be measured.

Pixel Responsiveness Lag (The lag from the time is takes for the pixels to change to show the image after it was processed by the monitor’s internal circuit board).

Because the quoted pixel responsiveness time provided by the manufacturer is usually found to be pretty accurate (after comparing our tests to their quoted times), on InputLag.com we only focus on reporting this number.

Poor) A lag of more than 66.6ms / more than 2 frames at 30Hz – Very noticeable/distracting lag. Early LCD’s from the 1990’s may be this bad, but they do not exist now.

If the monitor has one frame of lag, it won’t really be noticeable because there are 144 frames being shown every second. However, a monitor running at only 30 FPS, skipping one frame constantly from the input lag is going to be much more noticeable, and put you at a significant disadvantage.

There are a few main reasons for this, most notably is the lack of testing ability for higher framerates. Leo’s tool is limited to 1080p and 60Hz, while many of the top gaming monitors are way ahead of this, pushing 240Hz nowadays. It would not be accurate to be testing an expensive top-shelf gaming monitor with a native 240Hz refresh rate, with a tool that can only measure up to 60Hz. It forces you to measure the input lag of that 240Hz monitor at only 60Hz, which means the fastest it can possibly score is 16.67ms. Wait, what – the maximum visible display lag for 60Hz is 16.67ms? Yes.

For instance, if a 240Hz monitor is rated as “Excellent @240Hz”, it will still be rated “Excellent” at 60Hz. The refresh rate of a monitor has a direct impact on its input lag. A 60Hz monitor, for example, will never have a visible input lag below 16.67ms, because at 60Hz, the screen gets refreshed every 16.67ms (refresh to the bottom of the screen, see the next question for an explanation). So, if the overall input lag time is really 15ms, it doesn’t matter, because the lag time is less than the time for the screen to refresh the image, and it can’t be visibly measured. A 120Hz display halves that time to 8.3ms, and a 240Hz display further reduces it to 4.17ms.

This is a huge distinction that needs to be made. The web is full of misinformation concerning quoted “Input Lag” times, which often are only measuring the time it takes for the pixels to change from black to white, and is more of an indication of pixel response time rather than the true “input lag” that gamers are wanting to know for an advantage.

This is important to understand to get a good grasp of how monitors work and why there is always a difference in reported lag times. It also explains how some sites can quote an Input Lag time that is faster than the possible refresh time of the screen. LCD monitors refresh from top to bottom as seen below in the video.

Most people using Leo’s tool test the monitor and report the number from the middle of the screen, something that SMTT does as well. This is why the maximum visible display lag for 60Hz is 16.67ms, yet often gets reported as being lower for gaming displays running at 60Hz. If you test a 60Hz display with an exact quoted input lag time of 16.67ms (time to refresh to the last pixels at the bottom of the LCD panel), it should take roughly (just an estimate) 16.67ms/2 = 8.335ms to provide a reading in the middle of the display.

Output from Mouse/Keyboard/Controller -> Signal processed by Computer and Game -> Signal sent out to screen through HDMI/other cable (about 1/100th the speed of light [scienceline.ucsb.edu/getkey.php?key=2910]) -> monitor processes signal and sends to panel for display -> pixels on panel change to show image as intended.

What is highlighted in red is what we are measuring for the “Input Lag” of a display (TVs & Monitors). By using a tool to measure the screen going from white to black, it can only visibly measure

What is highlighted in blue is what I consider to be Physical Input Lag – the time it takes for your mouse/keyboard/controller to send the signal to your computer. There is significant room for variation here, hence why this category is also so important to gaming.

This is absolutely false. It’s true the human eye does have its own lag, and then there is the lag associated with reacting to what the eye sees (such as moving your thumb on a controller), but all of this takes place after the input lag described so far on this page. Factoring in this “human eye lag”, it would look something like this:

As you can see, the Input Lag of a display does matter. Any improvement in lag, whether it’s from the controller, the signal processing, the refresh rate, the computer itself, or even wearing the proper glasses – puts you at an advantage over someone who is on inferior equipment.

That being said, there is something to say about the lag times from human to human. Some of us are better at recognizing what is being displayed on a screen. Some of us are better at reacting to the change on a screen. This is why the pro player will win against a casual player 10 times out of 10 for a fast paced game – they have been practicing this talent, and may even have some sort of natural-born advantage (debatable). Either way, will shaving 10ms of lag off your game make you win every time? Probably not. But will shaving 10ms of lag off your game help you win more? Definitely.

This is the question with the most technical jargon to comprehend. Data in a cable (in the form of an electrical frequency) travels at about 1/100th the speed of light (source). So for any digital cable, we are talking about nanoseconds in lag, billionths of seconds. The lag is so small, and so insignificant, it makes no difference whatsoever to a professional gamer. When talking about other components of Input Lag, we are able to measure them in thousandths of seconds, so shaving off 10ms is a whole tenth of a second (it makes a difference). But cable speed is the most insignificant part of input lag by a large margin. What’s important to take away is that the monitor you purchase will always include a cable to support the highest refresh rate and resolution possible for that display. So this section shouldn’t matter too much, but for those interested here is the information anyway.

The following TVs, featured at the top of the page, deliver either the lowest lag I"ve measured among the TVs I"ve reviewed, the best picture quality for the money, or a combination of both.

There are actually three LG OLED TVs tied for the lowest lag on the chart, but we"re choosing the C1 because it"s the best value. The other two, the C2 and the G1, are both more expensive, and all three deliver very similar picture quality -- which happens to be the best we"ve ever tested. The C1 is a 2021 TV, but the gaming extras and other differences between it and the C2 from 2022 aren"t worth the price.

Note that its lag score here was measured with the special "Reduce input delay (input lag)" setting in the Boost position. Boost is only available for 60Hz sources, so you can"t use it with 120Hz games or VRR. With those sources you"ll need to use the Standard position, which is still an excellent 13ms.

Another high-end 2021 TV, this Samsung QLED model delivers the best picture quality of any TV we"ve reviewed that"s not based on OLED display tech. It can get brighter than any of the OLED TVs listed here, supports all the next-gen gaming features, and showed lower lag than any 2020 TV we"ve tested so far.

Game mode makes a difference, except when it doesn"t.As you can see in the table above, many TVs cut lag substantially when you turn on game mode, but plenty don"t. In general, expensive TVs with elaborate video processing get more of a benefit when you engage game mode.

Turning game mode on can hurt image quality (a little).TV makers" menus often refer to reduced picture quality. Reduced picture quality is generally the result of turning off that video processing. In my experience, however, the differences in image quality are really subtle with console gaming, and worth the trade-off if you want to minimize lag for a great gaming experience.

If the TV input where your console is connected is shared with other devices and you don"t want to remember to re-engage game mode all the time, an auto game-mode feature might be useful. And some cutting-edge

If you’re looking to get a new gaming monitor, whether 60Hz, 144Hz, 165hz or even 240Hz, then you’re most likely considering two very important specs. We don’t mean resolution as that’s a given and the first item on the list right next to screen size. We’re referring to input lag and response time. While most prospective gaming monitor shoppers know what refresh (or frame) rate means, quite a few people remain confused about the distinction between response time and input lag.

Additionally, while almost every gaming monitor has a response time listed in the spec section, input lag rarely makes an appearance. That’s because while the confusion exists, the two terms are very different. Manufacturers can easily calculate and test monitor response times at the factory, but input lag (or input latency) presents a much more complex issue. Many factors that go into input lag have nothing to do with the monitor or the production process used to make the display, and so manufacturers would be remiss if they made bold input lag claims.

Despite that, as someone interested in gaming and gaming monitors you should definitely educate yourself on these two related but distinct terms. That’s because if you opt for a cheap monitor that ends up having slow response or lots of lag then your gaming may well be ruined. Even monitors with high refresh rates can be slow in this regard. If they suffer from sluggish response time and high latency your games will present with problems like motion blur and ghosting. Additionally, controlling in-game actions will feel “off” and unresponsive. That’s why gamers really should learn more about response time and input lag plus how the two differ.

Quite a simple answer to that one. Response time forms a part of overall input latency. That most likely explains why so many people misunderstand that the two specs describe different but connected aspects of a gaming monitor. Another cause for confusion may originate in the fact that both refer to speed and have become part of the popular discussion around gaming monitors as things to consider for optimal monitor performance. Often mentioned in the same sentence, response time and input latency sometimes become conflated with each other.

Sure, both tell us important things about a gaming monitor’s speed, but from very different angles. Response time is entirely native to the monitor proper, while input lag or latency include the whole process from you pressing a button to a corresponding action occurring onscreen.

Distilled to their bare essence, both terms detail the speed with which images change on a display and react to your input. But that’s a very simplistic description that doesn’t do the topic justice, so let’s look at them up close.

Response describes the length of time a given monitor or panel needs to change the properties of each pixel. Since TFT LCDs consist of millions of pixels (or transistors), for example 8.3 million in a 4K monitor, speed is understandably of the essence. Response time tells us how long a monitor needs to turn a pixel from red to green, as an example. The faster, the more responsive the image updates. Faster means smoother display and allows for higher refresh rates.

Think of response time like this. You’re playing a first person game and decide to turn left, down an alley. Your monitor gets the data from your PC or console and needs to update the image you see to reflect the new graphics being loaded in. A monitor with 5ms technically does this five times slower than a 1ms screen. Of course, we’re talking about milliseconds so the difference may not be perceptible. But every little bit counts as games by nature need to be responsive, and like we said response time contributes to overall lag or delay.

Different gaming monitor panel types support slightly diverse response times, although advancing technology has helped narrow down gaps. The fastest response occurs on TN panels, which generally are the best for reflex-based gaming. Essentially all TN panels do 1ms these days, which is why they’re the only ones capable of 240Hz refresh rates, as well. VA and IPS panels usually come in at 2ms-5ms but provide better colors and viewing angles. We’ve discussed panel technologies if you want to know more.

TN panels carry out the least pixel processing of the three main panel types, explaining their high speeds. VA and IPS panels have been designed to ensure better colors, but that requires more processing – meaning delays. As the simplest mainstream panel type, TN manages the fastest response times by getting straight to the pixel, so to speak.

The total time required to show an action on the screen amounts to what is known as input lag. The word input mostly refers to you, the user. You press a key or click a button on a keyboard or controller and then expect a corresponding action on your gaming monitor (or TV). The time needed to show you that action equals input lag.

Input lag rises from a host of factors. From your controller or keyboard the signal moves to your PC or console. If you’re using wireless input devices that movement takes a little longer than with wired versions. Then your PC or console take time to process the data you gave them, then more time to send graphics info via a cable to your display. Generally, HDMI and DisplayPort have the same speed: light speed. So cables aren’t a major issue, but they’re a step. Then every monitor has processing units that accept signals and work to update the screen. Thus, the monitor’s internal circuitry introduces lag. Response time factors into latency as we mentioned above. That means the time a monitor needs to get a signal, process that signal, then change its pixels to depict visuals obviously adds latency.

Any image processing done on your monitor increases latency. Even if base response time is 1ms, should the monitor then add refinements like HDR, dynamic brightness/contrast, edge sharpening, local dimming and so forth – well, latency increases. Remember the basic rule: image processing means lag.

That’s why for gaming we recommend using PC mode or game mode. Those switch off most image processing to keep you close to raw response time on the monitor. How do we measure input lag? Also in milliseconds, but it’s a lot more than response time. Really good monitors like the BenQ EL2870U,  the 4K HDR monitor EW3270U, and 144hz gaming monitor EX2780Q with speakers clock in at 9ms-10ms based on third party reviews, but the average hovers somewhere between 15ms and 22ms for typical gaming monitors and gaming-minded TVs. You should not detect any negative effects with those latency figures, and your games will feel very responsive. It’s only when latency exceeds 40ms or so that people begin to notice sync issues. Anything over 50ms would be basically unplayable. Don’t laugh, lots of cheap monitors and TVs even now deliver performance slower than that, resulting in completely ruined gaming experiences.

When shopping for a gaming monitor do some research, read reviews, and check out the spec sheets. You’ll likely find out about each model’s response time easily enough, but reviews and forum posts will shed more light on input lag. Stay with reputable, established brands. Get monitors that specifically mention gaming, as good manufacturers won’t claim gaming-grade performance for slow monitors, it’s simple as that.

Also simple is the difference between response time and input latency. The former is local to the monitor and helps you understand how fast the panel is on its own. The latter refers to a much more comprehensive and useful number because it includes response time and illustrates the actual gaming experience you’ll have with a monitor or TV.

Overdrive and input lag definedSo what are input lag and inverse ghosting and what role does overdrive play in causing them? Thanks to the near universal silence on these matters from monitor manufacturers, facts are hard to come by.

The basics of overdrive are well-enough known as it’s a common technique for creating a cheap panel with a fast response time. If you’re not familiar with the basics of how an LCD panel works, you might want to read up on this feature, but overdrive is a technique that involves using higher levels of voltage to make the liquid crystals in a TFT panel change colour state more quickly.

Too much voltage will cause the pixels to overshoot the desired target state, and thus display an incorrect colour, so the voltage needs to be reduced before this happens. Overdriven LCD panels certainly have noticeably sharper, zippier image quality when displaying movement. However, close inspection of some overdriven monitors reveals that there"s something slightly rotten going on too, problems which have come to be known as input lag and inverse ghosting.

PVA panels, meanwhile, are renowned for their deep, inky blacks, vibrant colours and ultra-wide viewing angles. The third major panel type is IPS. It’s the most accurate of the bunch, but is costly to produce and has largely been relegated to expensive professional displays that focus on colour accuracy above all else.

Despite the many advantages of PVA panels, they’re tended to be weak in terms of response times. Until, that is, the first PVA panels with pixel overdrive technology began to appear around 2005.

Probably the best known of these was Dell"s 2405FPW, a 24-inch screen that shook up the industry by combing a glorious 1,920 x 1,200, 24in PVA panel manufactured by Samsung with a relatively affordable price tag.

forums were awash with complaints of its perceived lagginess.The 2405FPW was quite unlike any monitor we’d seen before. It was huge, impossibly vibrant and, with a 16ms response time, appeared quick enough for gaming. It quickly became the monitor to have for PC enthusiasts. Gradually, however, web forums began to buzz with rumours of the 2405FPW’s supposed ‘lagginess’.

This lagginess was distinct from pixel response. Rather than the screen displaying ‘ghosting’, glimpses of the previous frame or position of a window because the pixels didn’t change colour quickly enough, input lag referred to a perceived delay between the video signal being sent to the monitor and the resulting update of the image data on the screen.

In other words, the screen’s detractors claimed, there was a noticeable lag between the physical mouse input and the movement of the cursor or crosshair on the screen. On the desktop, this gave the 2405FPW a curiously sticky, disconnected feel. In games, particularly first person shooters, it made the 2405FPW borderline unusable for some lag-sensitive players.

Other screens soon became infamous for their tendency to suffer from input lag, most notably Samsung’s SyncMaster 244T, another 24-inch PVA monitor. Compared to the instantaneous output of an analogue CRT monitor, the process of translating a digital signal into an image across the pixel grid of an LCD panel will obviously result in at least some lag on all LCD monitors, but it seems clear that excessive input lag appears to only affect PVA panels with overdrive technology (with the exception of the closely related MVA panel type).

That said, the precise details of how overdrive technology causes input lag aren’t clear. We contacted Dell and Samsung to discuss the causes of the excess lag seen on certain PVA monitors, but both eventually declined to comment. Initially, we thought ignorance was probably to blame. Input lag has yet to become part of the standard lexicon when discussing TFTs – few in the industry are even aware of the problem. However, we’re pretty confident there are engineers and product managers at both companies who are. We pushed hard enough for answers to suspect that their silence was more a case of opting to keep quiet than of complete ignorance.

However, a monitor with low input lag, in my opinion, can make an impact when similar skill levels are involved. Higher resolutions and a better picture may be great for eye candy, but do very little to impact your gameplay. In fact, many professional gamers in my circle turn down resolution and settings while competing.

With that let"s discuss several great low-input-lag monitors that are at the top of their game for responsiveness. These include budget options, FreeSync, and G-Sync monitors, as well as IPS options.

I"m not going to put this list into any rigorous order as different monitors are better for different budgets and genres. However, all of these monitors have Input lags that are competition-worthy. I wouldn"t necessarily pick the monitor with the lowest input lag. Rather go with the monitor here that you like the best.

A few years ago IPS panels had a hurdle that few manufacturers could get over. Refresh rate. And while most gamers preferred an IPS monitor for watching movies or everyday work, many of them couldn"t get past the motion blur they"d see.

If there"s one downside, it"s that the brightness isn"t as high as many of the other IPS panels on the market right now reaching a high of around 350 cd/m2. For me, it was plenty.

Testing and numbers aside these monitors both look amazing on all the games I tested them on. Yes, you may get a small bit of backlight bleeding. For photo editing, the solid calibration and wide gamut backlight set it apart from similar options on the market, and with a low response time and input lag, it"s an ideal option for gamers.

This is an inexpensive IPS panel done right. It gives you that TN panel performance (use action mode) with fast response times and a great picture. I highly recommend you enable HDR. It definitely makes a huge difference. Backlight bleed will vary from panel to panel and, for me, was minimal with this one.

No, you don"t get quantum dots or true HDR 600, but you do get a 165Hz Ultra WQHD panel for the 34" ultra-wide at just $599 and a 27" 144Hz QHD curved monitor for just $260. These are not flagship prices, and therefore, you"re not getting a perfect experience here. However, you"re coming pretty close.

If you"re not looking for an IPS panel, FreeSync, or an integrated G-Sync monitor, then this is probably the one to own. It"s a little pricey for a 24" LED screen, but not compared to similar 144hz monitors. It can be adapted for both 3D and G-Sync.

While I really like the performance of the higher-priced / same panel Asus ROG Swift PG27UQ I couldn"t get past the fan. So, if you"re looking for a high-end gaming monitor with all the bells and whistles, I"d steer you towards Acer"s Predator model PBMIPHZX.

Cons: In spite of all the pros, this monitor is still only 1080p. Plus, the bezels are a bit thicker than some other options out there. So, I definitely wouldn"t recommend it for a double or triple monitor setup. In addition, this is a TN panel monitor. So, it"s certainly not for editing photos.

Console Input Lag for this is good with around an average of 13ms. That"s while running at 60Hz. While I"m not sure why you"d choose this for console, it is important to note that using it at 240Hz on PC shows considerably less lag.

There are, admittedly, a few monitors in this space with similar panels. If $500 seems like a lot, you may prefer something like the Aorus KD25F. It doesn"t include the BFI feature that the Zowie has, but it certainly has a few pros vs. the Zowie XL2546 (including price tag).

In terms of G-Sync monitors the Asus PG79Q is my favorite this year with the Acer XB271HU coming in at a close second. I found the PG279Q to just have slightly better quality for the panel. That being said, the Acer XB271HU"s stand is much improved vs last year"s version and doesn"t lose by much.

This monitor isn"t flawless, and this is a TN panel. It"s also a couple of years old at this point. So, viewing angles are not wide, but it is responsive and bright when placed in front of you. Ultimately, you"re getting great value for the price in a large 4k HDR monitor with FreeSync. I"d recommend it for all types of games.

Whether you"re looking for a low input lag console gaming monitor or simply want a PC gaming monitor with FreeSync, the Asus VG245H is a fantastic value. It has virtually no input lag and comes with a ton of features gamers will love.

It"s the modern version of the old ASUS VH236H use