VESA, the organization for computer displays that stands behind standards such as the DisplayPort interface, has a new certification program designed to help customers find better variable-refresh rate monitors. Unlike its previous HDR certification program, which measured things like peak brightness, the new specification for the Adaptive-Sync Display CTS test is designed specifically for variable refresh rate displays, such as care for problems such as flickering and missed shots.
Variable Refresh Rate (VRR) is a technology that allows the display to synchronize its refresh rate with the output of each device included in it, reducing the appearance of visual artifacts, screen breakage, and frame rate issues. When VRR support first appeared on graphics cards and monitors, it tended to be tied to specific vendors: G-Sync for Nvidia and FreeSync for AMD. But in 2014, VESA built its own Adaptive-Sync support into DisplayPort 1.2a based on technology provided by AMD, and now it’s a standard that is cross-compatible with GPUs from the three major manufacturers: Intel, AMD and Nvidia.
Nvidia and AMD already have certification tests for their own standards
Both Nvidia and AMD have long offered their own certification schemes for VRR displays using their own standards, but this is more of a wild west when it comes to the open Adaptive-Sync standard. When Nvidia began testing Adaptive-Sync monitors in 2019 as part of its G-Sync Compatible initiative, only 5.56 percent of the models it tested actually passed. They either did not offer a sufficiently wide range of refresh rates, or had other image quality problems such as flicker.
The new VESA certificate is intended to offer similar guarantees regarding the support of adaptive synchronization on a monitor or laptop. But unlike Nvidia or AMD certifications, this is an open source industry standard and its testing criteria are public.
“Obviously there are patented standards from GPU vendors, but they’ve never revealed the full scope of their tests,” said Roland Worcester, an Intel engineer and chairman of the VESA Task Force, which came out with its new test during a call. in Zoom. Take a look at Nvidia’s website, for example, and see that it says that the monitor must go through more than 300 tests to win a G-Sync logo, but there is less to come about exactly what those tests are. And this generates some confusion over the years, especially when it comes to criteria like “Realized HDR”.
“They have never disclosed the full scope of their tests.”
With its certification, VESA tests raw Adaptive-Sync performance, not GPU-specific standards such as FreeSync or G-Sync. For this reason, VESA expects its certification logos to often be accompanied by manufacturer-specific equivalents. The G-Sync logo tells you how the monitor will work with Nvidia’s GPU, but the VESA AdaptiveSync logo can tell you how the monitor will work with any Adaptive-Sync-compatible source.
Importantly, VESA’s Adaptive-Sync technology is only available for its own DisplayPort standard, which is used for monitors and laptops (including every time you transfer video via USB-C). Unfortunately, this will not help you choose one of the growing number of TVs that offer VRR support via HDMI 2.1, where the standards are even more like the Wild West.
But in addition to being more public, Wooster suggests that the new VESA certification standard maintains displays of a higher standard than these vendor-specific certificates. “We’ve seen some monitors that meet these certificates, that have flicker, that have flicker, and that don’t meet the gray-to-gray specifications we have here,” he says. In a subsequent email, he told me that he expected significantly fewer than half of the Adaptive-Sync monitors on the market to meet VESA standards, similar to what Nvidia discovered when it introduced its own Adaptive-Sync certification.
According to VESA certification, there are two compliance logos that displays can win. MediaSync is designed for monitors that you can use to watch videos or use to create content, while AdaptiveSync is aimed at game monitors. If their device passes these tests, manufacturers are allowed to place the appropriate logos in the product box, website or where they believe potential customers can see it. A display that fails the tests cannot use the logo, but manufacturers must not disclose the error publicly.
MediaSync logo focused on video playback. Image: VESA The AdaptiveSync logo is designed for game monitors. Image: VESA
The first of the two logos is called MediaSync. The focus here is on monitors to be able to play video content – with less than 1 ms of flicker – in each of the 10 major international frame rate standards (23.976, 24, 25, 29.97, 30, 47.952, 48, 50, 59.94 and 60 frames per second – where 23.976 is often typical of American movie content). It sounds like a simple question, but content at 24 frames per second can have real problems with playback on 60Hz displays, as the frames are not evenly distributed in the refresh rate of the screen. Three or two pulls down was a common way to deal with the problem (where the first frame is displayed twice, the second three times, the third twice, etc.), but it can create an unpleasant twitch. The MediaSync logo means that the monitor can use Adaptive-Sync to avoid such problems.
The second is the AdaptiveSync logo, which targets high-refresh game monitors. So, for starters, a monitor with the AdaptiveSync logo should be able to run at a maximum refresh rate of 144 Hz or more at natural resolution in the default default mode, and its adaptive refresh rate should be able to drop up to 60 Hz. This may not seem like a very low floor, but Wooster explains that if your frame rate drops lower, to 58 frames per second, for example, then the monitor is expected to use doubling frames to increase it to 116 frames per second. second and return it back to its adaptive sync range.
If the monitor can reach 144 Hz, then you will see a “Display 144” field to the right of the certification logo, but Wooster tells me that this number will reflect any maximum refresh rate of the monitor – whether it’s 144, 240 or 360Hz – at natural resolution.
An in-depth and open approach
It’s not enough to just be able to output this frequency range. In order to be certified, the monitor must be able to do it well. This means not displaying a level of flicker that is visible to the naked eye, even when the frame rate of the monitor changes rapidly. This means not missing frames – which can happen when the monitor provides input with support for a higher frame rate than the panel actually supports.
VESA also takes a detailed approach to how it measures response time or the time it takes to update monitor pixels. It’s common in the whole industry to see this, expressed as gray-to-gray response time, or the approximate time it takes to change a pixel from one shade of gray to another. If the response time is too slow, monitors may display “ghosts” in which the remnants of a previous image are still visible on the screen while the pixels struggle to cope. To receive the AdaptiveSync logo, the monitor must have a response time of less than 5 ms.
5ms may seem high compared to the 1ms response time that many manufacturers claim their monitors are capable of. But in real tests, such as those conducted by Rtings, the response time is usually much higher than 1 ms. Rtings usually classify any response time below 6 ms as a “good value”.
Manufacturers like to make these statements for a response time of 1 ms, because they are not as strict with their testing as independent reviewers such as Rtings or VESA test centers. Some manufacturers, says Wooster, can make a number of changes from gray to gray and then choose the best result. Others may benefit from the fact that a warmer panel can react significantly faster than a cold one. Overdrive can be used to achieve a faster response time on paper, but at the expense of ugly visual artifacts.
The first certified monitors will be added to VESA’s list today
VESA’s solution is to measure a variety of different transitions from gray to gray (20 in total) and take an average value instead of choosing the best result. The tests are performed at an ambient temperature between 22.5 and 24.5 degrees Celsius (72.5 – 76 Fahrenheit). Monitors are given time to reach a stable temperature first, and limits are placed on how much overshoot and downgrade a monitor can show and still pass.
Wooster declined to say how much VESA members expect to pay for their devices to eventually be certified for MediaSync or AdaptiveSync (the fee is the same whether a display goes through or doesn’t work), but the first certified monitors must appear on the website of VESA from today. He cites the number of devices currently carrying one of VESA’s HDR certificates as an example of the amount of monitors and laptops we may eventually see carrying the new AdaptiveSync logos.
Given VESA’s great list of members from across the display industry, these little orange and blue logos can quickly become a hallmark of quality when buying your next monitor or laptop.
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