lcd panel refresh rate factory

Recently, we often have customers ask us about the refresh rate of led screen, most of them are for filming needs, such as XR virtual photography, etc. I would like to take this opportunity to talk about this issue To answer the question of what is the difference between a high refresh rate and a low refresh rate.

Refresh rate and frame rate are very similar. They both stands for the numbers of times a static image is displayed per second. But the difference is that the refresh rate stands for the video signal or display while the frame rate stands for the content itself.

The refresh rate of a LED screen is the number of times in a second that the LED screen hardware draws the data. This is distinct from the measure of frame rate in that the refresh rate for LED screens includes the repeated drawing of identical frames, while frame rate measures how often a video source can feed an entire frame of new data to a display.

The frame rate of video is usually 24, 25 or 30 frames per second, and as long as it is higher than 24 frames per second, it is generally considered smooth by the human eye. With recent technological advances, people can now watch video at 120 fps in movie theaters, on computers, and even on cell phones, so people are now using higher frame rates to shoot video.

Refresh rate can be divided into vertical refresh rate and horizontal refresh rate. The screen refresh rate generally refers to the vertical refresh rate, that is, the number of times the electronic beam repeatedly scanned the image on the LED screen.

In conventional terms, it is the number of times that the LED display screen redraws the image per second. The screen refresh rate is measured in Hertz, usually abbreviated as “Hz”. For example, a screen refresh rate of 1920Hz means that the image is refreshed 1920 times in one second.

What you see on the LED video wall is actually multiple different pictures at rest, and the motion you see is because the LED display is constantly refreshed, giving you the illusion of natural motion.

Because the human eye has a visual dwelling effect, the next picture follows the previous one immediately before the impression in the brain fades, and because these pictures are only slightly different, the static images connect to form a smooth, natural motion as long as the screen refreshes quickly enough.

A higher screen refresh rate is a guarantee of high-quality images and smooth video playback, helping you to better communicate your brand and product messages to your target users and impress them.

Conversely, if the display refresh rate is low, the image transmission of the LED display will become unnatural. There will also be flickering “black scan lines”, torn and trailing images, and “mosaics” or “ghosting” displayed in different colors. Its impact in addition to video, photography, but also because tens of thousands of light bulbs flashing images at the same time, the human eye may produce discomfort when viewing, and even cause eye damage.

A higher led screen refresh rate tells you the ability of a screen’s hardware to reproduce the screen’s content several times per second. It allows the motion of images to be smoother and cleaner in a video, especially in dark scenes when showing fast movements. Other than that, a screen with a higher refresh rate will be more suitable for the content with a more significant number of frames per second.

Typically, a refresh rate of 1920Hz is good enough for most LED displays. And if the LED display needs to display high speed action video, or if the LED display will be filmed by a camera, the LED display needs to have a refresh rate of more than 2550Hz.

The refresh frequency is derived from the different choices of driver chips. When using a common driver chip, the refresh rate for full color is 960Hz, and the refresh rate for single and dual color is 480Hz. when using a dual latching driver chip, the refresh rate is above 1920Hz. When using the HD high level PWM driver chip, the refresh rate is up to 3840Hz or more.

HD high-grade PWM driver chip, ≥ 3840Hz led refresh rate, screen display stable and smooth, no ripple, no lag, no sense of visual flicker, not only can enjoy the quality led screen, and effective protection of vision.

In professional use, it is critical to provide a very high refresh rate. This is especially important for scenes geared towards entertainment, media, sporting events, virtual photography, etc. that need to be captured and will certainly be recorded on video by professional cameras. A refresh rate that is synchronized with the camera recording frequency will make the image look perfect and prevent blinking. Our cameras record video usually at 24, 25,30 or 60fps and we need to keep it in sync with the screen refresh rate as a multiple. If we synchronize the moment of camera recording with the moment of image change, we can avoid the black line of screen change.

LED display refresh rate of not less than 3840Hz, the camera to capture the picture screen stability, can effectively solve the image of the rapid motion process of trailing and blurring, enhance the clarity and contrast of the image, so that the video screen delicate and smooth, long time viewing is not easy to fatigue; with anti-gamma correction technology and point-by-point brightness correction technology, so that the dynamic picture display more realistic and natural, uniform and consistent.

Therefore, with the continuous development, I believe the standard refresh rate of led screen will transition to 3840Hz or more, and then become the industry standard and specification.

One thing we should be aware of is that, unlike grayscale, there is a certain risk of too high a refresh rate. When the refresh rate gets higher, it demands more and more quality of LEDs. If the quality of the LED is not good, it will not be able to withstand the impact of high refresh rates and will be easily damaged. Normally, we should set the refresh rate below the maximum value set at the factory, such as 3840Hz, if the refresh rate is too high, it will affect the life of the LED.

Whether you want to use an indoor or outdoor advertising LED screen for branding, video presentations, broadcasting, or virtual filming, you should always choose an LED display screen that offers a high screen refresh rate and synchronizes with the frame rate recorded by your camera if you want to get high-quality images from the screen, because then the painting will look clear and perfect.

It’s natural for anyone shopping desktop monitors to be swayed by size, shape, resolution and color quality. But depending on your business needs, you may also want to consider a less flashy feature: the monitor’s refresh rate.

Refresh rate is the frequency at which the screen updates with new images each second, measured in hertz (cycles per second). The content may look steady on the display, but what the viewer can’t see is how fast the content is changing — up to 360 times a second. The higher the refresh rate, the smoother the visual quality.

Super high monitor refresh rates aren’t all that important for office workers focused on lighter computing like word processing, spreadsheets and emails. But in more visual professions like creative production and game development, a high refresh rate for monitors is invaluable.

The standard refresh rate for desktop monitors is 60Hz. But in recent years, more specialized, high-performing monitors have been developed that support 120Hz, 144Hz and even 240Hz refresh rates, which ensure ultra-smooth content viewing, even for the most demanding visual processing needs.

Just buying a high refresh rate monitor doesn’t mean the display quality will magically improve. The monitor’s refresh rate reflects the maximum rate at which the display can change the visuals. What happens on the screen depends on the frame rate of the output — the number of video frames that are sent to the display each second.

A 120Hz monitor has obvious benefits, though, for modern gaming platforms that animate at 100 fps or higher. A high refresh rate helps the screen keep pace with the high-twitch inputs of players and translate them into super smooth actions on screen.

When refresh rate and frame rate are mismatched, it can result in something called screen tearing. If the computer’s graphic card is pushing out more frames than the monitor’s refresh rate can handle at a given moment, users may see two half-frames on the screen at once, bisected horizontally and slightly misaligned. In short, it doesn’t look good. Games are usually configured to automatically match the PC’s graphics capabilities to avoid tearing, but running high-action visuals more slowly than intended makes for a compromised viewing and playing experience.

Response time — the time it takes for a pixel to change color — also plays a role in refresh rate. A monitor can only refresh as quickly as the LCD display can make those rapid-fire color shifts.

Particularly for fast-paced visuals, higher refresh rates and faster pixel response times reduce ghosted visuals, and ideally eliminate them. With slower tech, a high-pace action sequence may come with trailing images that result in softer, even blurry on-screen visuals.

The appeal of high refresh rates is obvious for at-home gamers looking for a responsive, hyperrealistic playing experience. And this leisure use is part of a vast global industry. SuperData reported that the video gaming industry generated roughly $140 billion in 2020, up 12 percent from $120 billion in 2019. Statista estimates there are now more than 3 billion gamers worldwide.

In the U.S. alone, the video game industry employs 220,000 people across all 50 states, according to the Entertainment Software Association. That’s a lot of game developers, graphic artists and playtesters working in front of monitors, most of them in need of optimal visual quality and speed at their workstations. While 60Hz refresh rates may work fine for people in finance and human resources — and even the clerical side of gaming companies — people on the visual and testing side need at least 120Hz to do their jobs well.

And it’s not just gaming. While the film industry has long produced movies at 24 fps, that frame rate is a relic of times when there were different technical restraints on cameras and projection, so a faster frame rate required more expensive film. The 24 fps standard has stuck around largely because that’s what the public is used to. Today, filmmakers are increasingly pushing frame rates as high as 120 fps.

High-performance monitors with high refresh rates come with obvious visual improvements, but monitor upgrades in general bring a broader range of business benefits.

High refresh rate monitors with high response times also tend to come with other premium features, such as full support for USB-C connections. With a single cable, the user can connect their PC to a monitor that functions as a USB hub for peripheral devices. This negates the need for expensive and often clunky docking stations, and can significantly reduce the number of cables at each workstation. In addition to tidier, streamlined workspaces, this also reduces the demand for IT support. With fewer connectors and devices, you tend to get fewer problems.

Around the workplace, anyone in a visually creative role will see immediate benefits from a higher refresh rate. And while those in non-visual roles probably won’t see any difference, the key may be futureproofing.

When IT and information systems (IS) teams plan capital purchases, they need to look several years ahead for potential technical requirements down the road. While high-refresh monitors may have a defined user community right now, it’s likely more use cases and worker needs will develop. Monitors with low refresh rates can’t get better, but higher-refresh monitors can serve your display needs both now and in the future.

As of Test Bench 1.2, there are two separate test boxes that we evaluate, and they are tested at the same time. The first is the Refresh Rate box to determine the display"s native and max refresh rate depending on its connection type and the signal sent. We test it with a test PC using an NVIDIA graphics card, usually an RTX 3000 Series card, and the test is done at the monitor"s native resolution.

As of Test Bench 1.2, there are two separate test boxes that we evaluate, and they are tested at the same time. The first is the Refresh Rate box to determine the display"s native and max refresh rate depending on its connection type and the signal sent. We test it with a test PC using an NVIDIA graphics card, usually an RTX 3000 Series card, and the test is done at the monitor"s native resolution.

The max refresh rate denotes the maximum frequency the monitor can refresh the image, as supported by the manufacturer. It includes the factory overclock that comes with many gaming monitors. Note that this only looks at officially supported overclock modes; it may be possible to overclock most monitors through overclocking tools and custom resolutions, but we don"t check for this.

We check this max refresh rate with both DisplayPort and HDMI connections, and this is done by sending an 8-bit color depth signal. For many monitors, you can only achieve the max refresh rate over a DisplayPort connection because DP 1.2 and 1.4 connections have higher bandwidth than the older HDMI 2.0 bandwidth, which is still found on many monitors.

We repeat the same tests to determine the max refresh rate, but by sending a 10-bit signal. It"s important for HDR games as HDR requires 10-bit color depth, so with this test, you can see the max refresh rate at which you can play. Due to HDMI 2.0"s bandwidth limitations, many monitors have a limited refresh rate over HDMI, and once again, you"ll likely need to use the DisplayPort connection to use the monitor to its full potential.

The second test we do is to determine the VRR formats and the range at which it works. We use PCs with RTX 3000 Series and RX6600 XT graphics cards to test the G-SYNC and FreeSync support, and we also use NVIDIA"s G-SYNC Pendulum Demo and check games to make sure VRR is working properly across the refresh rate range of the display. The Pendulum Demo can be used to test any VRR format supported by the PC and monitor. We look to see if there"s any screen tearing or other unusual artifacts in the demo.

We check for FreeSync compatibility with a PC with an AMD Radeon graphics card, usually RX6600 XT. This test is important if you"re planning on using the variable refresh rate feature with an AMD Radeon graphics card or with an Xbox One S/X or Xbox Series S|X. There are three possible results for this test:

The simplest way to validate that a display is officially G-SYNC compatible is to check the "Set up G-SYNC" menu from the NVIDIA Control Panel. G-SYNC will automatically be enabled for a certified compatible display, and it"ll say "G-SYNC Compatible" under the monitor name. Most of the time, this works only over DisplayPort, but with newer GPUs, it"s also possible to enable G-SYNC over HDMI with a few monitors and TVs, but these are relatively rare.

Compatible (Tested):Monitors that aren"t officially certified but still have the same "Enable G-SYNC, G-SYNC Compatible" setting in the NVIDIA Control Panel get "Compatible (Tested)" instead of "NVIDIA Certified". However, you"ll see on the monitor name that there isn"t a certification here. There really isn"t a difference in performance between the two sets of monitors, and there could be different reasons why it"s not certified by NVIDIA, including NVIDIA simply not testing it. As long as the VRR support works over its entire refresh rate range, that means the monitor works with an NVIDIA graphics card.

For this test, like with the two previous ones, we make sure G-SYNC is enabled from the NVIDIA Control Panel and use the NVIDIA Pendulum Demo to ensure G-SYNC is working correctly. If we have any doubts, we"ll also check with a few games to make sure it"s working with real content as well.

This test represents the maximum frequency at which the variable refresh rate feature can be enabled and work properly. We test this using the NVIDIA Pendulum Demo, and most of the time the "VRR Maximum" is just the same result as the "Max Refresh Rate", but there are some cases where the overclock causes some issues with the VRR.

Our VRR Minimum test checks for the minimum frame rate at which the VRR feature is still working properly. Like the previous test, we check this using the NVIDIA Pendulum Demo, gradually reducing the frame rate until the screen starts tearing. If a monitor supports both FreeSync and G-SYNC, we also check the range of each. If there"s any difference between them, we put the widest range as the result and note the difference in the text.

Because we test for the effective frame rate and not the actual refresh rate of the display, our minimum refresh rate is frequently lower than the minimum reported by the manufacturer. It"s because many monitors support a feature known as Low Framerate Compensation (LFC). If the framerate of the source drops below the minimum refresh rate of the display, the graphics card automatically multiples frames to bring the framerate back within the refresh rate range of the display. Since we look at the effective VRR range, we don"t differentiate between monitors that use LFC and monitors that can reduce their actual refresh rate.

We repeat the tests above over both DisplayPort and HDMI connections and list which connections the VRR feature works on. Most of the time, the VRR works over both connections, but because the maximum refresh rate can be different over HDMI, we also include in the text if there are differences in the range. Also, we"ll include in the text which connections you need for the G-SYNC or FreeSync VRR to work, as many G-SYNC compatible displays only work over DisplayPort connections, but higher-end monitors with HDMI 2.1 bandwidth now support G-SYNC over both connections.

While refresh rate has the biggest impact on the clarity and fluidity of motion on screens, you also need a good response time to have smooth motion handling. We measure this as part of our motion blur test, and it refers to the time it takes for the display"s pixels to switch from one state to another across a variety of transitions (for example, from showing black to showing white).

The relation between them is found when looking at what we call frame time. The frame time refers to the length of time a frame is shown on screen. For example, a 120Hz monitor has 120 cycles per second, so every frame appears every 8.33 ms. If your screen"s average pixel response time is higher than this, it can cause blurriness since the pixels rarely have time to complete their transition before switching to displaying the next frame. Because of this, it"s important to consider our entire motion section and not only the refresh rate to evaluate the motion capabilities of a monitor.

The refresh rate also has an impact on the input lag of a monitor. There"s more of a direct relation here than with the response time, as the lower refresh rate helps result in lower input lag. A 60Hz monitor results in a frame time of 16.67 ms, and because we measure the input lag in the middle of the screen, the minimum input lag for a 60Hz display is 8.33 ms (it takes half the frame time to refresh in the middle of the screen). However, a 360Hz monitor has a frame time of 2.78 ms, which a minimum input lag of 1.39 ms, so you get a much more responsive feel with a higher refresh rate monitor.

There isn"t much to do to enable the maximum refresh rate of your monitor. It"s mostly a plug-and-play affair and doesn"t require much tinkering to get working right, as long as your graphics card can take advantage of the maximum refresh rate.

Change the refresh rate setting on your computer. You can do this either through your graphics card"s driver settings or in Windows through the display adapter properties panel found in your display settings.

Some high-end gaming monitors have an Overclock feature that allows you to boost your screen"s refresh rate beyond its standard rating. You can access this in the monitor"s on-screen display menu. You will need to change the refresh rate in your operating system to match the overclock afterward.

Some games and other applications that execute in full-screen mode ignore the system setting for refresh rate and might require you to enable your monitor"s maximum refresh rate through their internal settings.

The refresh rate is the number of times the monitor"s screen refreshes every second. Higher frequencies produce smoother and clearer motion and enable more responsive interaction. It"s most important for video games, but it offers an improvement for almost every type of usage as long as the content or device supplies a matching frame rate to the refresh rate of the display. We test to see the maximum refresh rate the monitor can function at its native resolution, and we also check to see which variable refresh rate formats it supports, as well as the range at which it works.

The focus of this study is a description of features and artifacts of the LCD technology which are supposed to be relevant for psychophysical and neuroscientific experiments in general. A wide range of different monitor technologies and determinants of the temporal signal are compared. Three recent studies [30]–[32] approach the topic from the opposite side by focussing on well defined psychophysical requirements which they relate to only a few aspects on one or two LCD panels. In the following, we will briefly review these works and compare their approaches and results to the present study.

Kihara and colleagues [30] compare the performance in three psychophysical experiments which were performed on one LCD and two CRT devices, respectively. They statistically analyze the experimental results, fail to find significant differences for most of the conditions, and conclude that the three displays elicited similar performance profiles.

Wang and Nikolić [31] compared one CRT monitor and two different LCD panels, an old and a new model, with respect to both their spatial and temporal properties. The authors report that for the new LCD monitor the level of accuracy of timing and intensity was comparable, if not better to the benchmark CRT monitor, while the old LCD panel had a number of issues with respect to accuracy.

The study by Lagroix and colleagues [32] also analyses temporal properties. The authors investigate psychophysical estimates of visible persistence of stimuli immediately after their assumed disappearance on the display device. In their experiments, observers performed forced choice tasks on these stimuli, where a shutter controlled that the stimulus could not be seen during the period when it was (intendedly) displayed. They compared performance using a CRT and an LCD monitor. While there was considerable visible persistence on the CRT for white stimuli on black background, the authors did not find any perceptual persistence on the LCD panel.

Our study, however, demonstrates a number of artifacts due to improper DCC with some substantial effects on the luminance transition signal, such as luminance stepping or substantial overshoots. It remains important future work to study these artifacts with experimental paradigms as developed by Lagroix and colleagues, as it is likely that some of the artifacts presented in this work have considerable impacts on visual persistence.

A significant point is that the phosphors on a CRT screen have their "persistence" designed to support a particular fairly narrow range of refresh rates. The phosphors could be made to have really long persistence (seconds), so there would be no serious flicker down to even maybe a 5 second refresh interval, but then, since the phosphors can only be "turned on" and not "turned off", you wouldn"t be able to see motion much faster than that. (Some early CRT terminals used long-persistence phosphors, with the characters "drawn" on the screen instead of scanned. This didn"t provide very fast "refresh", but it only had to be as good as a 10 CPS Teletype.)

LCDs have the property that they can be turned on or off, at some relatively high rate, and once set one way or the other they have a relatively long persistence, on the order of a second or so. For this reason they can support a wide range of refresh rates.

LCDs are "scanned" via an X-Y matrix of wires, with a pixel at each point where two wires cross. Only one pixel can be manipulated at a time. The voltage on a pixel must be maintained long enough to "charge" the pixel, so that it will hold the charge until refreshed, and all pixels must be visited on each refresh cycle.

And, in addition to the charge time, the liquid inside needs time to mechanically reorient its crystal structure (though, at a physics level, this reorientation is tied at least partially to the "charge" time). Both of these factors place an upper limit on refresh rate.

VESA Adaptive-Sync Display Compliance Test Specification establishes clear benchmarks for consumers to compare variable refresh rate performance of displays supporting the VESA Adaptive-Sync protocol

BEAVERTON, Ore. – May 2, 2022 – The Video Electronics Standards Association (VESA®) today announced the first publicly open standard for front-of-screen performance of variable refresh rate displays. The VESA Adaptive-Sync Display Compliance Test Specification (Adaptive-Sync Display CTS) provides for a comprehensive and rigorous set of more than 50 test criteria, an automated testing methodology and performance mandates for PC monitors and laptops supporting VESA’s Adaptive-Sync protocols.

The Adaptive-Sync Display CTS also establishes a product compliance logo program comprising two performance tiers: AdaptiveSync Display, which is focused on gaming with significantly higher refresh rates and low latency; and MediaSync Display, which is designed for jitter-free media playback supporting all international broadcast video formats. By establishing the VESA Certified AdaptiveSync Display and MediaSync Display logo programs,

VESA will enable consumers to easily identify and compare the variable refresh rate performance of displays supporting Adaptive-Sync prior to purchase. Only displays that pass all Adaptive-Sync Display CTS and VESA DisplayPort™ compliance tests can qualify for the VESA Certified AdaptiveSync Display or MediaSync Display logos.

More than two years in development, VESA’s Adaptive-Sync Display CTS and logo programs were established with contributions by more than two dozen VESA member companies spanning the display ecosystem, including major OEMs that supply displays, graphic cards, CPUs, panels, display drivers and other components.

In 2014, VESA added Adaptive-Sync protocols to the VESA DisplayPort video interface standard to enable smoother, tear-free images for gaming and jitter-free video playback, as well as enable lower power and greater efficiency in displaying content rendered at a wide range of frame rates. Since this introduction, VESA’s Adaptive-Sync technology has seen widespread adoption across the display industry and is now supported by all major GPU chipset vendors. However, while many PC and laptop displays currently support Adaptive-Sync protocols, until now there had been no open standard in measuring the level of performance or quality of Adaptive-Sync support for any given display. VESA’s AdaptiveSync Display and MediaSync Display logo programs address this need, providing the consumer with a clear benchmark for front-of-screen visual performance of variable refresh rate operation established by testing in compliance with the Adaptive-Sync Display CTS.

The VESA Adaptive-Sync Display CTS includes more than 50 automated display performance tests covering several key variables, including refresh rate, flicker, gray-to-gray response time (including limits on overshoot and undershoot to ensure high-quality images), video frame drop, and video frame rate jitter. As required by the VESA Adaptive-Sync Display CTS, all displays must be tested in the factory shipping state or default factory mode configuration, as well as tested in ambient room temperature, in order to ensure the display is evaluated and certified under realistic user conditions. In addition, all displays that meet the requirements for VESA AdaptiveSync Display and MediaSync Display logo certification must also be tested and certified to VESA’s DisplayPort standard. The majority of desktop and laptop GPUs introduced within the last two years are capable of supporting VESA’s Adaptive-Sync protocols. VESA encourages consumers to check with their GPU vendor to verify that their GPU and software driver enables Adaptive-Sync operations with VESA Certified AdaptiveSync Display and MediaSync Display products by default.

The VESA Certified AdaptiveSync Display logo features a performance tier, which includes a value indicating the maximum video frame rate that is achievable for Adaptive-Sync operation tested at the display’s factory default settings at native resolution (e.g., AdaptiveSync Display 144 or 240). For the VESA Certified MediaSync Display logo, there is no performance tier since the emphasis of product certification for this logo is on the absence of display jitter rather than high frame rate. Display vendors wishing to participate in the VESA Certified AdaptiveSync Display or MediaSync Display logo program can send their products for testing at any of VESA’s approved Authorized Test Centers (ATCs).

Note to Editors:Adaptive-Sync (with a hyphen between Adaptive and Sync) is used for explaining Adaptive-Sync operation and Adaptive-Sync protocols, as well as used to refer to the Adaptive-Sync Compliance Test Specification (Adaptive-Sync CTS). AdaptiveSync (without either hyphen or space) is used to represent the VESA Certified AdaptiveSync logo program. Adaptive Sync (with space between Adaptive and Sync) is a generic term used to refer to variable refresh rate.

If you’re a gamer, it’s always been a challenge to balance the performance of your graphics card with your monitor. For many years people have had to live with issues like “tearing”, where the image on the screen distorts and “tears” in places creating a distracting and unwanted experience. Tearing is a problem caused when a frame rate is out of sync with the refresh rate of the display. The only real option historically has been to use a feature called Vsync to bring both in sync with one another, but not without introducing some issues of its own at the same time which we will explain in a moment. Back in 2014 – 15 we saw a step change in how refresh rates are handled between graphics card and monitor and the arrival of “variable refresh rate” technologies. NVIDIA and AMD, the two major graphics card manufacturers, each have their own approach to making this work which we will look at in this article. We are not going to go in to mega detail about the graphics card side of things here, there’s plenty of material online about that. We instead want to focus on the monitor side of things a bit more as is our interest at TFTCentral.

As an introduction, monitors typically operate at a fixed refresh rate, whether that is common refresh rates like 60Hz, 120Hz, 144Hz or above. When running graphically intense content like games, the frame rate will fluctuate somewhat and this poses a potential issue to the user. The frame rate you can achieve from your system very much depends on the power of your graphics card and PC in general, along with how demanding the content is itself. This can be impacted by the resolution of your display and the game detail and enhancement settings amongst other things. The higher you push your settings, the more demand there will be on your system and the harder it might be to achieve the desired frame rate. This is where an issue called tearing can start to be a problem as the frame rate output from your graphics card can’t keep up with the fixed refresh rate of your monitor. Tearing is a distracting image artefact where the image becomes disjointed or separated in places, causing issues for gamers and an unwanted visual experience.

At the most basic level ‘VSync OFF’ allows the GPU to send frames to the monitor as soon as they have been processed, irrespective of whether the monitor has finished its refresh and is ready to move onto the next frame. This allows you to run at higher frame rates than the refresh rate of your monitor but can lead to a lot of problems. When the frame rate of the game and refresh rate of the monitor are different, things become unsynchronised. This lack of synchronisation coupled with the nature of monitor refreshes (typically from top to bottom) causes the monitor to display a different frame towards the top of the screen vs. the bottom. This results in distinctive ‘tearing’ on the monitor that really bothers some users. Even on a 120Hz or 144Hz monitor, where some users claim that there is no tearing, the tearing is still there. It is generally less noticeable but it is definitely still there. Tearing can become particularly noticeable during faster horizontal motion (e.g. turning, panning, strafing), especially at lower refresh rates.

The solution to this tearing problem for many years was the ‘VSync ON’ option which essentially forces the GPU to hold a frame until the monitor is ready to display it, as it has finished displaying the previous frame. It also locks the frame rate to a maximum equal to the monitor’s refresh rate. Whilst this eliminates tearing, it also increaseslag as there is an inherent delay before frames are sent to the monitor. On a 120Hz monitor the lag penalty is half that of a 60Hz monitor and on a 144Hz monitor is even lower. It is still there, though, and some users feel it disconnects them from game play somewhat. When the frame rate drops below the refresh rate of the monitor this disconnected feeling increases to a level that will bother a large number of users. Some frames will be processed by the GPU more slowly than the monitor is able to display them. In other words the monitor is ready to move onto a new frame before the GPU is ready to send it. So instead of displaying a new frame the monitor displays the previous frame again, resulting instutter. Stuttering can be a major problem when using the Vsync on option to reduce tearing.

During Vsync ON operation, there can also sometimes be a sudden slow down in frame rates when the GPU has to work harder. This creates situations where the frame rate suddenly halves, such as 60 frames per second slowing down to 30 frames per second. During Vsync ON, if your graphics card is not running flat-out, these frame rate transitions can be very jarring. These sudden changes to frame rates creates sudden changes in lag, and this can disrupt game play, especially in first-person shooters.

To overcome these limitations with Vsync, both NVIDIA and AMD have introduced new technologies based on a “variable refresh rate” (VRR) principle. These technologies can be integrated into monitors allowing them to dynamically alter the monitor refresh rate depending on the graphics card output and frame rate. The frame rate of the monitor is still limited in much the same way it is without a variable refresh rate technology, but it adjusts dynamically to a refresh rate to match the frame rate of the game. By doing this the monitor refresh rate is perfectly synchronised with the GPU. You don’t get the screen tearing or visual latency of having Vsync disabled, nor do you get the stuttering or input lag associates with using Vsync. You can get the benefit of higher frame rates from Vsync off but without the tearing, and without the lag and stuttering caused if you switch to Vsync On.

NVIDIA were first to launch capability for variable refresh rates with their G-sync technology. G-sync was launched mid 2014 with the first screen we tested being the Asus ROG Swift PG278Q. It’s been used in many gaming screens since with a lot of success.

Traditionally NVIDIA G-sync required a proprietary “G-sync module” hardware chip to be added to the monitor, in place of a traditional scaler chip. This allows the screen to communicate with the graphics card to control the variable refresh rate and gives NVIDIA a level of control over the quality of the screens produced under their G-sync banner. As NVIDIA say on their website: “Every G-sync desktop monitor and laptop display goes through rigorous testing for consistent quality and maximum performance that’s optimized for the GeForce GTX gaming platform”.

This does however add an additional cost to production and therefore the retail price of these hardware G-sync displays, often in the realms of £100 – 200 GBP compared with alternative non G-sync models. Even higher when you consider the new v2 module which is often £400 – 600 additional cost. This is often criticized by consumers who dislike having to pay the “G-sync Tax” to get a screen that can support variable refresh rates from their NVIDIA graphics card. There have been some recent changes to this in 2019 which we will discuss later, in relation to allowing support for G-sync from other non-module screens.

NVIDIA G-sync screens with the hardware module generally have a nice wide variable refresh rate (VRR) range. You will often see this listed in the product spec as something like “40 – 144Hz”, or confirmed via third party testing. We have seen lots of FreeSync screens, particularly from the FreeSync 1 generation, with far more limited VRR ranges. NVIDIA also seem to be at the forefront of bringing the highest refresh rate gaming monitors to market first, so you will often see the latest and greatest models with G-sync support a fair while before alternative FreeSync options become available.

Overclocking of refresh rates on some displays has been made possible largely thanks to the G-sync module. The presence of this module, and absence of a traditional scaler has allowed previously much slower panels to be successfully overclocked to higher refresh rates. For instance the first wave of high refresh rate 34″ ultrawide screens like the Acer Predator X34 and Asus ROG Swift PG348Q had a 100Hz refresh rate, but were actually using older 60Hz native panels. The G-sync module allowed a very good boost in refresh rate, and some excellent performance improvements as a result. This pattern continues today, as you will often see screens featuring the G-sync module advertised with a normal “native” refresh rate, and then an overclocked refresh rate where the panel has been boosted. For instance there’s quite a lot of 144Hz native screens which can be boosted to 165Hz or above thanks to the G-sync module.

The above is allowing an overclock of the LCD panel, while operating the G-sync module within its specifications. We should mention briefly the capability to also overclock the G-sync module itself, pushing it a little beyond its recommended specs. This has only been done once in this way once as far as we know, with the LG 34GK950G. That screen featured a 3440 x 1440 resolution panel with a natively supported 144Hz refresh rate, but it was combined with the v1 G-sync module. This was presumably to help avoid increasing costs of using the v2 module, especially as providing HDR support was not a priority. With the 3440 x 1440 @144Hz panel being used, this was beyond the bandwidth capabilities of the v1 module and so natively the screen will support up to 100Hz. It was however possible to enable an overclock of the G-sync module via the OSD overclocking feature on the monitor, pushing the refresh rate up to 120Hz as a result. The panel didn’t need overclocking here, only the G-sync module. We mention this only in case other monitors emerge where manufacturer opt to use the v1 module for cost saving benefits, but need to push its capabilities a little beyond its native support. It does seem that the chip is capable of being overclocked somewhat if needed.

From our many tests of screens featuring the hardware G-sync module, the response times of the panels and the overdrive that is used seems to be generally very reliable and consistent, producing strong performance at both low and high refresh rates. This seems to be more consistent than what we have seen from FreeSync screens so far where often the overdrive impulse is impacted negatively by changes to the screens refresh rate. NVIDIA also talk about how their G-sync technology allows for “variable overdrive” where the overdrive is apparently tuned across the entire refresh rate range for optimal performance.

G-sync modules also often support a native blur reduction mode, dubbed ULMB (Ultra Low Motion Blur). This allows the user to opt for a strobe backlight system if they want, in order to reduce perceived motion blur in gaming. It cannot be used at the same time as G-sync since ULMB operates at a fixed refresh rate only, but it’s a useful extra option for many of these G-sync module gaming screens. Of course since G-sync/ULMB are an NVIDIA technology, it only works with specific G-sync compatible NVIDIA graphics cards. While you can still use a G-sync monitor from an AMD/Intel graphics card for other uses, you can’t use the actual G-sync or ULMB functions.

It should be noted that the real benefits of G-sync really come into play when viewing lower frame rate content, around 45 – 60fps typically delivers the best results compared with Vsync on/off. At consistently higher frame rates as you get nearer to 144 fps the benefits of G-sync are not as great, but still apparent. There will be a gradual transition period for each user where the benefits of using G-sync decrease, and it may instead be better to use the ULMB feature if it’s been included, which is not available when using G-sync. Higher end gaming machines might be able to push out higher frame rates more consistently and so you might find less benefit in using G-sync. The ULMB could then help in another very important area, helping to reduce the perceived motion blur caused by LCD displays. It’s nice to have both G-sync and ULMB available to choose from certainly on these G-sync enabled displays. Soon after launch NVIDIA added the option to choose how frequencies outside of the supported range are handled. Previously it would revert to Vsync on behaviour, but the user now has the choice for various settings including Fast Sync, V-sync, no synchronisation and allowing the application to decide.

FreeSync was not launched until a bit later than NVIDIA G-sync, on 19th March 2015, with the first screen we tested being the BenQ XL2730Z. Like NVIDIA G-sync this is all about providing support for variable refresh rates, reducing tearing, and without the lag and stuttering that older Vsync options created. Unlike NVIDIA G-Sync’s method, which requires the adoption of discrete chips, FreeSync focuses on the link interface standards. It has integrated the DisplayPort Adaptive-Sync industry standard, which allows real-time adjustment of refresh rates through the DisplayPort 1.2a (and above) interface. The newest HDMI interface specification also supports FreeSync. Although FreeSync synchronization technology does not require adding extra chips to the monitors, it must be matched with DisplayPort or HDMI compatible monitors and Radeon graphics cards in order to function. This is one advantage of FreeSync over G-sync, as it can be supported over HDMI if you need as well as DisplayPort.

Many displays with Adaptive-Sync / FreeSync offer somewhat limited real-life support for VRR. In some cases there is a narrow VRR operating range, where the VRR feature may only work when the game frame rate is in a narrow, very specific range which is often not the case, as game frame rates vary significantly from moment to moment. In addition, not all monitors go through a formal certification process (certainly from the initial FreeSync 1 generation), display panel quality varies, and there may be other issues that prevent gamers from receiving a noticeably-improved experience. In theory you can use FreeSync from any screen capable of supporting Adaptive-Sync, but the actual VRR performance can really vary.

Due partly to the lack of certification standards for the FreeSync 1 generation, AMD later released FreeSync 2 in January 2017. This thankfully does include a “meticulous monitor certification process to ensure exceptional visual experiences” and guarantees things like support for Low Frame Rate Compensation (LFC) and support for HDR inputs. AMD also talk about monitors with FreeSync 2 as having low latency. You will see many screens carry the FreeSync 2 badge nowadays, meaning you can have more faith in their VRR performance at the very least.

The control of the monitors overdrive impulse seems to be a bit varied with FreeSync displays. Early models (and potentially some that are available today) had a bug which meant that if you connected the screen to a FreeSync system, the overdrive would be turned off completely! Even disabling the FreeSync option in the AMD control panel didn’t help, you had to instead “break” the FreeSync chain by using a non-FreeSync card, or a different connection or something. Thankfully that early bug hasn’t been something we’ve seen problems with in more recent times. Many manufacturers also include an option to disable and enable FreeSync within the monitor OSD which can help create that firmer option to disable it if you ever want to, independent to the graphics card software.

We have seen quite a lot of variable performance when it comes to pixel response times from FreeSync screens, and they do seem to be a lot more hit and miss than G-sync equivalents. On G-sync screens you commonly get response times that remain strong and consistent across all refresh rates. Sometimes the response times will be controlled more dynamically, increasing the overdrive impulse as the refresh rate goes up. On FreeSync screens we have seen many where the overdrive impulse seems to be controlled in the opposite way oddly, where it is turned down when the refresh rate goes up. This can help eliminate overshoot problems but can often lead to slower response times at the higher refresh rates where you really need them to be faster! You will again have to rely on third party testing like that in our reviews, but it’s something we’ve seen from quite a few FreeSync screens.

On NVIDIA G-sync screens the ULMB blur reduction feature is associated with the hardware chip added to the monitor, and so many G-sync capable screens also offer ULMB as well. Since there is no added chip on FreeSync screens manufacturers have to provide blur reduction modes entirely separately, which has meant they are far less common on FreeSync screens than on G-sync screens. Again we are reliant on the manufacturers to focus on this if blur reduction is a requirement.

Because FreeSync 2 can support an HDR input source, it has unfortunately led to what we consider to be a fairly widespread abuse of the HDR term in the market. We’ve talked in a separate article (well worth a read!) about our concerns with the VESA DisplayHDR standards, and in particular their HDR400 certification. It doesn’t take much to label a screen with HDR400 support and mislead consumers in to thinking they are buying a screen which will offer them a good HDR experience. Unfortunately most of these so-called HDR screens offer no real HDR benefits, for reasons explained in our other article. If you see an NVIDIA G-sync screen marketed with HDR, it almost certainly has a high end local dimming solution (at least at the time of writing it does). Whereas a FreeSync 2 screen with HDR might be meaningless.

AMD FreeSync can support dynamic refresh rates between 9 and 240Hz but the actual supported ranges depend on the display, and this does vary. When you connect the display to a compatible graphics card, with the relevant driver package installed the display is detected as FreeSync compatible and presents options within the software. You will normally see the supported FreeSync range listed, and can turn the setting on and off as shown above. You may also have to enable FreeSync from within the monitor OSD on many screens before this option is available in the graphics card. You may also need to configure it within a given application as explained on AMD’s website here.

We don’t want to go into too much depth about game play, frame rates and the performance of FreeSync here as we will end up moving away from characteristics of the monitor and into areas more associated with the operation of the graphics card and its output. FreeSync is a combined graphics card and monitor technology, but from a monitor point of view all it is doing is supporting this feature to allow the graphics card to operate in a new way. We’d encourage you to read some of the FreeSync reviews and tests online as they go into a lot more detail about graphics card rendering, frame rates etc as well.

In January 2019 NVIDIA surprised the market by opening up support for VRR from their graphics cards on other non-G-sync displays featuring the Adaptive-Sync capability. This created a whole new world of opportunities for consumers, who can now benefit from the dynamic refresh rate performance from their NVIDIA card, but are no longer restricted to selecting a screen with the added G-sync hardware module. There are far more Adaptive-Sync/FreeSync displays available, and often with more connections and additional features available, not to mention at a comparatively lower retail cost. You have to have a modern NVIDIA graphics card and operating system to make use of this G-sync support, needing a GTX 10-series or RTX 20-series of later.

Because there is such a wide range of FreeSync screens on the market, NVIDIA have come up with an additional certification scheme called “G-sync Compatible“. They will test monitors  that deliver a baseline VRR experience and if the certification is passed, they will activate their VRR features automatically in the NVIDIA control panel. NVIDIA keep an up to date list of monitors that are officially G-sync Compatible, and they’ll continue to evaluate monitors and update the support list going forward. G-sync Compatible testing validates that the monitor does not show blanking, pulsing, flickering, ghosting or other artefacts during VRR gaming. They also validate that the monitor can operate in VRR at any game frame rate by supporting a VRR range of at least 2.4:1 (e.g. 60Hz-144Hz), and offer the gamer a seamless experience by enabling VRR by default. So a screen which carries this official “G-sync Compatible” badge should in theory offer reliable VRR experience at least. It at least has been through many tests and checks from NVIDIA to earn that badge.

Many displays with Adaptive-Sync offer somewhat limited real-life support for VRR. In some cases there is a narrow VRR operating range, where the VRR feature may only work when the game frame rate is in a narrow, very specific range. Which is often not the case, as game frame rates vary significantly from moment to moment. In addition, not all monitors go through a formal certification process, display panel quality varies, and there may be other issues that prevent gamers from receiving a noticeably-improved experience. In theory you can use G-sync from any screen capable of supporting Adaptive-Sync, but the actual VRR performance can really vary. This is also an issue when using AMD graphics cards for the same reason, if the screens VRR experience is not up to much.

NVIDIA say that they have tested over 400 Adaptive-Sync displays and found that only a small hand full could be certified under their “G-sync compatible” scheme (currently up to 14 at the time of writing), which implies that the rest offer a lower level of VRR experience. For VRR monitors yet to be validated as G-sync Compatible, a new NVIDIA Control Panel option will enable owners to try and switch the tech on – it may work, it may work partly, or it may not work at all. We will label this more generically as “G-sync Support” for simplicity. You can find plenty of tests and reports online from owners of different FreeSync screens and how they perform from NVIDIA graphics cards.

For the absolute best gaming experience NVIDIA recommend NVIDIA G-sync and the newly certified “G-sync Ultimate” monitors: those with the v2 G-sync hardware modules and that have passed over 300 compatibility and quality tests, and feature a full refresh rate range from 1Hz to the display panel’s max refresh rate, plus other advantages like variable overdrive, refresh rate overclocking, ultra low motion blur display modes, and industry-leading HDR with 1000 nits, Full Array Local Dimming (FALD) backlights and DCI-P3 colour gamut. You can see from the image above that this includes (and at the time of writing is currently limited to) the Asus ROG Swift PG27UQ, Acer Predator X27 and new 65″ BFGD HP Omen X Emerium 65 screen. Clearly these are the very expensive, high end HDR displays but these are classified as the ultimate in gaming experience by NVIDIA.

We expect many of the cutting edge gaming screens to appear with traditional G-sync module inclusion before FreeSync alternatives are available, including the latest and greatest high refresh rates. That is part of the market where the G-sync module seems to have a firm grasp right now. Usage of the G-sync v2 module also seems to be a requirement so far for delivering the top-end HDR experience in the monitor market, with all current FALD backlight models featuring this chip. We expect to see the v2 module used primarily for the really top-end, premium screens with high resolutions, high refresh rates and likely FALD HDR support. The v2 module may also be used in some modern screens where the resolution and refresh rate demand it (and need a DisplayPort 1.4 interface), but where top-end HDR is not necessarily a requirement. This might be cost prohibitive in some cases, as the chip is expensive to start with. While there are savings to be made by not including HDR or a FALD backlight, the v2 module cost may be prohibitive in some cases.

In our opinion we feel that the v1 module also has some life left in it. Yes, there are some screens which are now pushing the bandwidth boundaries due to high resolutions and refresh rates – the LG 34GK950G being a prime example. However, there are still plenty of smaller screens or models with a resolution and refresh low enough to make the v1 chip viable. The v1 chip can’t support HDR, although most of the screens advertised as supporting HDR in the market don’t offer any meaningful HDR anyway. We expect to see the v1 module used for various middle end screens for a little while longer.

The 12.9-inch Liquid Retina XDR display has an IPS LCD panel supporting a resolution of 2732 by 2048 pixels for a total of 5.6 million pixels with 264 pixels per inch. To achieve Extreme Dynamic Range required an entirely new display architecture on iPad Pro. The all new 2D mini-LED backlighting system with individually controlled local dimming zones was the best choice for delivering the extremely high full-screen brightness and contrast ratio, and off-axis color accuracy, that creative professionals depend on for their workflows.

The Liquid Retina XDR display improves upon the trade-offs of typical local dimming systems, where the extreme brightness of LEDs might cause a slight blooming effect because the LED zones are larger than the LCD pixel size. This display is designed to deliver crisp front-of-screen performance with its incredibly small custom mini-LED design, industry leading mini-LED density, large number of individually controlled local dimming zones, and custom optical films that shape the light while maintaining image fidelity and extreme brightness and contrast.

Additionally, custom algorithms run on the advanced display engine of the M1 chip, working at the pixel level to control the mini-LED and LCD layers of the display separately, treating them as two distinct displays. These proprietary algorithms coordinate the mini-LED and LCD layers across transitions to deliver the optimal visual experience. Transitional characteristics of local dimming zones, such as a slight blur or color change while scrolling against black backgrounds, are normal behavior.

The Liquid Retina XDR display delivers P3 wide color. The color gamut afforded by the P3 primaries is larger than sRGB, offering richer and more saturated colors, especially with certain reds, yellows, and greens. The result is rich and vibrant color that’s also used in the digital cinema industry. Every Liquid Retina XDR display is also calibrated at the factory for color, brightness, gamma, and white point for a consistent visual experience.

ProMotion technology automatically adjusts the display refresh rate up to 120 Hz (twice the rate of typical LCD displays) to the optimal rate for the content. The result is ultra-smooth scrolling and incredible responsiveness on the display, whether you’re using your finger or Apple Pencil. True Tone technology subtly adjusts the white balance onscreen to match the color temperature of the light around you, so images on the display look as natural as on a printed page. The cover glass on the Liquid Retina XDR display has an on-axis reflection of 1.8 percent due to a custom antireflective coating. As a result, iPad Pro delivers industry-leading reflectivity for a more comfortable viewing experience indoors and out.

NVIDIA G-SYNC Displays with Reflex have the world’s first and only system latency measurement tool that detect clicks coming from Reflex compatible mice and measure the time for the resulting pixels (gun muzzle flash) to change on screen. With tear-free refresh rates up to 360 Hz, exceptional responsiveness, built-in esports mode, and stunning image quality, NVIDIA G-SYNC® displays will change the way you look at competitive gaming.

Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is switched ON. Vertical ridges etched on the surface are smooth.

A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directlybacklight or reflector to produce images in color or monochrome.seven-segment displays, as in a digital clock, are all good examples of devices with these displays. They use the same basic technology, except that arbitrary images are made from a matrix of small pixels, while other displays have larger elements. LCDs can either be normally on (positive) or off (negative), depending on the polarizer arrangement. For example, a character positive LCD with a backlight will have black lettering on a background that is the color of the backlight, and a character negative LCD will have a black background with the letters being of the same color as the backlight. Optical filters are added to white on blue LCDs to give them their characteristic appearance.

LCDs are used in a wide range of applications, including LCD televisions, computer monitors, instrument panels, aircraft cockpit displays, and indoor and outdoor signage. Small LCD screens are common in LCD projectors and portable consumer devices such as digital cameras, watches, calculators, and mobile telephones, including smartphones. LCD screens have replaced heavy, bulky and less energy-efficient cathode-ray tube (CRT) displays in nearly all applications. The phosphors used in CRTs make them vulnerable to image burn-in when a static image is displayed on a screen for a long time, e.g., the table frame for an airline flight schedule on an indoor sign. LCDs do not have this weakness, but are still susceptible to image persistence.

Each pixel of an LCD typically consists of a layer of molecules aligned between two transparent electrodes, often made of Indium-Tin oxide (ITO) and two polarizing filters (parallel and perpendicular polarizers), the axes of transmission of which are (in most of the cases) perpendicular to each other. Without the liquid crystal between the polarizing filters, light passing through the first filter would be blocked by the second (crossed) polarizer. Before an electric field is applied, the orientation of the liquid-crystal molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic (TN) device, the surface alignment directions at the two electrodes are perpendicular to each other, and so the molecules arrange themselves in a helical structure, or twist. This induces the rotation of the polarization of the incident light, and the device appears gray. If the applied voltage is large enough, the liquid crystal molecules in the center of the layer are almost completely untwisted and the polarization of the incident light is not rotated as it passes through the liquid crystal layer. This light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts thus constituting different levels of gray.

The chemical formula of the liquid crystals used in LCDs may vary. Formulas may be patented.Sharp Corporation. The patent that covered that specific mixture expired.

Most color LCD systems use the same technique, with color filters used to generate red, green, and blue subpixels. The LCD color filters are made with a photolithography process on large glass sheets that are later glued with other glass sheets containing a TFT array, spacers and liquid crystal, creating several color LCDs that are then cut from one another and laminated with polarizer sheets. Red, green, blue and black photoresists (resists) are used. All resists contain a finely ground powdered pigment, with particles being just 40 nanometers across. The black resist is the first to be applied; this will create a black grid (known in the industry as a black matrix) that will separate red, green and blue subpixels from one another, increasing contrast ratios and preventing light from leaking from one subpixel onto other surrounding subpixels.Super-twisted nematic LCD, where the variable twist between tighter-spaced plates causes a varying double refraction birefringence, thus changing the hue.

LCD in a Texas Instruments calculator with top polarizer removed from device and placed on top, such that the top and bottom polarizers are perpendicular. As a result, the colors are in