Wednesday October 05, 2022

VRR monitors have become ubiquitous. VESA’s certification now wants them to be good

VESA, the computer display association behind standards such as the DisplayPort interface has a new certification program. It’s designed to help customers choose better variable refresh rate monitors. The new AdaptiveSync Display Compliance Specification (or AdaptiveSync Display CTS), is designed for variable refresh rate monitors. It is not the HDR certification program that VESA previously used to measure peak brightness. VRR support was initially limited to graphics cards and monitors from specific manufacturers. VESA added native Adaptive-Sync support to DisplayPort 1.2a in 2014 using technology provided by AMD. Now it’s a standard that is cross-compatible with all three major manufacturers: Nvidia, Intel, and AMD.
Nvidia and AMD have offered their own certification schemes to VRR displays using their standards for a long time. However, it’s more difficult to get certified to use the open Adaptive-Sync standard. Nvidia began testing Adaptive-Sync monitors in 2019 as part its “G-Sync Compatible” initiative. Only 5.56 percent of models tested passed. They didn’t offer enough refresh rates or had other issues such as flickering.
The new certification by VESA is intended to provide similar assurances about a laptop’s Adaptive-Sync support. It’s open-source and the testing criteria are public, unlike Nvidia’s or AMD’s certifications.
“There are obviously proprietary standards from GPU vendors, but they have never disclosed the full extent to their tests,” Roland Wooster (Intel engineer and chairman of VESA task team that created the new test), tells me over a Zoom phone call. You can see Nvidia’s website and see that it states that a monitor must pass over 300 tests in order to earn a G-Sync logo. However, it is less transparent about what those tests are. This has caused some confusion over time, especially when it comes to criteria such as “Lifelike HDR.”
VESA certifies raw Adaptive-Sync performance and not GPU-specific standards like FreeSync or G-Sync. For that reason, VESA expects its certification logos to often sit alongside manufacturer-specific equivalents. A G-Sync logo will tell you how a monitor performs with an Nvidia GPU, while a VESA Adaptive-Sync Logo can tell you how a screen will perform with any Adaptive-Sync capable source.
Importantly, VESA’s Adaptive-Sync technology is only available for its DisplayPort standard. This standard is used across laptops and monitors (including when you transmit video via USB-C). It won’t help you choose one of the growing number of TVs that support VRR via HDMI 2.1, where standards are more elusive.
Wooster says that VESA’s new certification standards are more public than vendor-specific certifications. He says that he has seen monitors that failed to meet the gray-to grey specs and that had flickering, jitter or other issues. He then sent me a follow-up email to inform me that he expects significantly less of the Adaptive-Sync-monitors on the market to comply with VESA standards. This is similar to Nvidia’s own certification for Adaptive-Sync display monitors.
Two compliance logos are available for displays that have been certified by VESA. MediaSync is for monitors that you use to watch videos, or for content creation. AdaptiveSync is for gaming monitors. Manufacturers are allowed to place the logos on the product’s packaging, website, or anywhere else they think potential customers might see them if the device passes these tests. The logo cannot be used on a display that fails to pass the tests, but manufacturers are not required to publicly disclose any failures.

MediaSync logo, which focuses on video playback. Image: VESA

Image: VESA

MediaSync is the first of the two logos. MediaSync is the first of the two logos. It focuses on making sure that monitors can play back video content with less than 1ms jitter at each of the ten international frame rate standards (23.976 (24.97), 30, 47.952, 48.50, 50, 59.942, and 60fps — 23.976 has been a common frame rate for American film content). Although it sounds simple, 24fps content can cause problems on 60Hz displays. This is because the frames are not evenly divided into the refresh rate of your screen. The three-two pull down method was used to solve the problem. This meant that the first frame was displayed twice, the second twice, and the third three times. However, it can cause juddering. A MediaSync logo indicates that a monitor can use Adaptive-Sync in order to avoid such issues.
The second logo is the AdaptiveSync, which is aimed towards high-resolution gaming monitors. A monitor bearing the AdaptiveSync logo must be able run at a maximum refresh speed of 144Hz at native resolution in factory default mode. Its adaptive refresh rate must be able go down to 60Hz. This might seem like a low floor, but Wooster explains how a monitor with an AdaptiveSync logo would need to be able to run at a maximum refresh rate of 144Hz or more at native resolution in factory default mode. Then, it would be expected to use frame-doubling, which will bring it up to 120fps and restore its adaptive sync range.
If a monitor is capable of reaching 144Hz, you will see a “Display144” box to right of the certification logo. But Wooster tells us that this number will reflect any monitor’s maximum refresh rates — whether they are 144, 240 or 360Hz — at native resolution.
It is not enough to be capable of displaying this range of frame rates. A monitor must be capable of displaying this range of framerates well in order to be certified. This means that the monitor must not show flicker that is visible to the naked eye. It also means not dropping frames, which can occur when a monitor supports higher frame rates than the panel can actually support.
VESA also has a detailed approach to measuring response time, which is the time it takes for a monitor’s pixels to update. This is often referred to as a “gray-to-gray” response time. This is the time it takes for a color to change from one to another. Monitors that have slow response times can show ghosting, where the remnants of an image are visible on the screen as the pixels struggle with keeping up. A monitor must have a response time below 5ms to be eligible for the AdaptiveSync logo.
5ms may seem long compared to the 1ms response time that many monitor manufacturers claim they can achieve. However, in real-world tests like those done by Rtings, the response times are often much higher than 1ms. Rtings considers any response time below 6ms to be “good value”.
Manufacturers love to claim 1ms response time because they aren’t as rigorous in their testing as independent reviewers such as Rtings or VESA’s testing centers. Wooster states that some manufacturers might do a variety of gray-to–gray changes, then cherry-pick the best results. Some might be able to benefit from the fact a warmer panel responds significantly faster than a cold panel. Although overdrive can be used to speed up the response time on paper, it can also lead to ugly visual artifacts.
VESA’s solution to this problem is to measure a variety gray-to-gray transitions (20 total) and to average them rather than picking the best. The ambient temperature is between 22.5 and 24.5, or 72.5 to 76 degrees Fahrenheit. Monitors are allowed to cool down before testing. Limits are set on the monitor’s ability to show enough to pass.
Wooster declined the opportunity to reveal how many VESA members he expects will pay to have their devices MediaSync or AdaptiveSync certified. The fee is the same regardless of whether a display passes, but the first certified monitors will be listed on VESA’s website beginning today. He points to the number of devices currently carrying HDR certifications by VESA as an example of how many monitors and laptops might soon sport the new Adaptive-Sync logos.
These little orange and blue logos could soon become a crucial mark of quality when you buy your next monitor or laptop, given VESA’s impressive list of members from all walks of the display industry.

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