VRR monitors are becoming ubiquitous, now VESA certification wants to make them good

VESA, the computer display organization behind standards like the DisplayPort interface, has a new certification program designed to help customers find better variable refresh rate monitors. Unlike his previous HDR certification programwhich measured things like maximum brightness, the new Adaptive-Sync Display Compliance Test Specification (or Adaptive-Sync Display CTS) is designed specifically for variable refresh rate displays, monitoring issues such as flickering and dropped frames.

Variable Refresh Rate (VRR) is a technology that allows a display to synchronize its refresh rate with the output of any device plugged into it, reducing the appearance of visual artifacts, screen tearing, and blurring. frame timing issues. When VRR support first started appearing on graphics cards and monitors, it tended to be tied to specific manufacturers: G-Sync for Nvidia and FreeSync for AMD. But in 2014, VESA integrated native Adaptive-Sync support into DisplayPort 1.2a based on technology provided by AMD, and now it’s a standard compatible with graphics processors from all three major manufacturers: IntelAMD and Nvidia.

Both Nvidia and AMD have long offered their own certification systems for VRR displays using their proprietary standards, but it’s more of a Wild West as far as the Adaptive-Sync open standard goes. When Nvidia started testing Adaptive-Sync monitors back in 2019 under its “G-Sync Compatible” initiative, only 5.56% of the models tested passed. Either they didn’t offer a wide enough range of refresh rates, or they had other image quality issues like flickering.

The new VESA certification is designed to provide similar assurances of Adaptive-Sync support for a monitor or laptop. But unlike Nvidia or AMD certifications, it is an open source industry standard, and its the test criteria are public.

“Obviously there are proprietary standards from GPU vendors, but they’ve never disclosed the full extent of their testing,” Roland Wooster, an Intel engineer and chairman of the VESA task force that came up with his new test, told me. , during a Zoom call. . Watch Nvidia’s website, for example, and you’ll see it says a monitor has to go through over 300 tests to earn a G-Sync logo, but it’s less clear what exactly those tests are. And it’s generated some confusion over the years, especially when it comes to criteria such as “realistic HDR”.

With its certification, VESA tests the raw performance of Adaptive-Sync, rather than GPU-specific standards like FreeSync or G-Sync. For this reason, VESA expects its certification logos to often sit alongside manufacturer-specific equivalents. A G-Sync logo tells you how a monitor will work with an Nvidia GPU, but a VESA AdaptiveSync logo can tell you how a monitor will work with any Adaptive-Sync compatible source.

It’s important to note that VESA’s Adaptive-Sync technology is only available for its own DisplayPort standard, which is used on monitors and laptops (including anytime you transmit video via USB-C) . Unfortunately, this won’t help you choose one of the growing numbers of TVs that offer VRR support via HDMI 2.1 where standards are more of a wild west.

But, in addition to being more public, Wooster suggests that the new VESA certification standard holds displays higher than those vendor-specific certifications. “We’ve seen monitors that have passed these certifications that have flicker, have jitter, and don’t meet the gray-to-gray specs that we have here,” he says. In a follow-up email, he tells me he expects less than half of the Adaptive-Sync monitors on the market to meet VESA standards, similar to what Nvidia found when it introduced its own certification for Adaptive-Sync displays.

As part of VESA certification, there are two compliance logos that displays can earn. MediaSync is for monitors that you can use to watch videos or create content, while AdaptiveSync is for gaming monitors. If their device passes these tests, manufacturers are allowed to stick relevant logos on the box of the product, website or wherever they think potential customers might see it. A screen that fails the tests cannot use the logo, but manufacturers do not need to publicly disclose a failure.

The MediaSync logo, focused on video playback.
Picture: VESA

The AdaptiveSync logo is for gaming monitors.
Picture: VESA

The first of the two logos is called MediaSync. The goal here is to ensure that monitors are capable of playing video content – with less than 1ms of jitter – at each of the 10 major international frame rate standards (23.976, 24, 25, 29.97 , 30, 47.952, 48, 50, 59.94 and 60 fps – where 23.976 has often been typical for cinematic content in America). It sounds like a simple request, but 24fps content can cause real problems when playing on 60Hz displays, as the frames don’t split evenly across the screen’s refresh rate. Three-two pull 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 annoying jerkiness. A MediaSync logo means a monitor can use Adaptive-Sync to prevent such issues.

The second is the AdaptiveSync logo, which is for high refresh rate gaming monitors. So to start with, a monitor with an AdaptiveSync logo should be able to run at a maximum refresh rate of 144Hz or higher at native resolution in factory default mode, and its adaptive refresh rate should be able to go down to 60Hz. Doesn’t sound like a very low floor, but Wooster explains that if your frame rate drops lower, to 58 fps for example, then a monitor should use frame doubling to bring it down to 116 fps and back into its adaptive sync range.

If a monitor can go up to 144Hz, you’ll see a “Display 144” box to the right of the certification logo, but Wooster tells me that number will reflect a monitor’s maximum refresh rate, whether it’s 144, 240, or 360Hz. — at native resolution.

Simply being able to display this range of frame rates is not enough. To be certified, an instructor must be able to do it well. This means not displaying a level of flicker visible to the naked eye, even when a monitor’s frame rate changes rapidly. This means no dropped frames – which can happen when a monitor provides an input that supports higher frame rates than a panel actually supports.

VESA also takes a detailed approach to how it measures response time, or the time it takes for a monitor’s pixels to update. Industry-wide, it’s common to see this expressed as a “gray-to-gray” response time, or roughly the time it takes for a pixel to change from one shade from gray to another. If response times are too slow, monitors can exhibit “ghosting,” where remnants of a previous frame are still visible on a screen as pixels struggle to keep up. To earn an AdaptiveSync logo, a monitor will need to have a response time of less than 5ms.

5ms might seem high compared to the 1ms response times that many manufacturers claim their monitors are capable of. But in real-world tests, like those led by Rtingsresponse times are typically well over 1ms. Rtings generally classifies any response time below 6ms as a “good value”.

Manufacturers like to make these claims about response times around 1ms because they’re not as rigorous in their testing as independent reviewers like Rtings or VESA test centers. According to Wooster, some manufacturers may perform a number of gray-to-gray changes and then select the best result. Others might benefit from the fact that a warmer panel can react significantly faster than a cooler panel. Overdrive can be used to achieve faster response time on paper, but at the expense of ugly visual artifacts.

VESA’s solution is to measure a variety of different gray to gray transitions (20 in total) and take an average, rather than picking the best result. The tests are carried out at an ambient temperature between 22.5 and 24.5 degrees Celsius (72.5 – 76 Fahrenheit). Monitors have time to reach a stable temperature first, and limits are imposed on how much overshoot and undershoot a monitor is able to display and pass.

Wooster declined to say how many VESA members it expects to pay to have their devices eventually MediaSync or AdaptiveSync certified (fees are the same whether a display passes or fails), but the first certified monitors should appear on the VESA website from today. It points to the number of devices that currently carry one of the VESA’s HDR Certifications as an example of the amount of monitors and laptops we might eventually see sporting the new AdaptiveSync logos.

Considering the VESAs great list of members of the entire display industry, those little orange and blue logos could quickly become an essential mark of quality when shopping for your next monitor or laptop.

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