New levels of Adaptive-Sync performance tackle misleading response times, flicker
So you’re looking at a monitor or laptop that says it has Adaptive-Sync or variable refresh rates. Maybe it’s Nvidia G-Sync or AMD FreeSync. Perhaps the vendor has gone into enough detail to include an Adaptive-Sync range, indicating the refresh rate range, as well as a response time figure and an overdrive feature promising extra-smooth video playback. But then you see a bunch of other monitors and laptops claiming the same thing. How do you know which screen will provide a better multimedia experience?
To help, the Video Electronics Standards Association (VESA) on Monday launched a certification program for PC monitors and laptop displays with Adaptive-Sync. The Adaptive-Sync Display CTS (Adaptive-Sync Display CTS) Compliance Test Specification aims to provide more information about screen anti-tearing technology.
The program, which has already certified some products, has more than 50 criteria for its two tiers: MediaSync Display, which focuses on video playback and requires an Adaptive-Sync range of at least 48-60Hz, and Adaptive-Sync Display, which is gaming-focused and requires an Adaptive-Sync rage of at least 60-144Hz.
A closer look at Adaptive-Sync performance
In 2014, VESA, a nonprofit group of hardware, software, computer, and component manufacturers that also sets the standards for DisplayPort, DisplayHDR, and VESA monitor media, added the Adaptive-Sync protocols to the DisplayPort video interface. Adaptive-Sync, which includes screens like Nvidia G-Sync and AMD FreeSync, is supposed to make video playback smoother by eliminating screen tearing, shaking, and flickering. Adaptive-Sync also seeks to reduce power consumption and efficiency when it comes to content playing at different frame rates.
Adaptive-Sync is now available on all types of monitors, including gaming and general purpose ones. It is also supported by major GPU vendors. Sockets from Nvidia and AMD provide additional optimizations for their graphics cards and may have other image quality requirements, depending on the type of G-Sync or FreeSync.
In an effort to provide a more detailed look at the Adaptive-Sync performance expected from a monitor or laptop under default settings, VESA – after two years of development with over two dozen members including Nvidia, AMD , Intel, and manufacturers of displays, display drivers, processors, and other components, is launching an Adaptive-Sync certification program with more stringent requirements. You can be an Adaptive-Sync, G-Sync and/or FreeSync display without the new MediaSync Display or Adaptive-Sync Display standards. But earning one of the new logos means the monitor has undergone extensive VESA testing, which we’ll get to shortly.
But before that, it’s worth noting that monitors require DisplayPort to get one of the certifications. This prevents HDMI-only Adaptive-Sync monitors from earning the new logo. The move gets more interesting when you consider that HDMI 2.1 introduced variable refresh rates into the standard.
Increased requirements for both levels
The most basic requirements of the new tiers are the defined Adaptive-Sync ranges. The MediaSync display level requires an Adaptive-Sync range that goes as low as at least 48 Hz and as high as at least 60 Hz. For the game-centric Adaptive-Sync display level, the range is more wide from 60 to 144 Hz.
But that’s just the beginning of what a monitor has to go through to reach one of the VESA logos.
To achieve MediaSync or Adaptive-Sync certification, a display must exhibit less than 1ms of judder, which is well below what is supposed to be visible to the human eye, according to VESA.
This figure must be achieved in 10 international frame rate standards: 23.976 Hz (Hollywood film); 24, 30 and 60Hz (usually content shot on consumer cameras, like YouTube videos or something that plays locally), 25Hz (UK TV), 29.97Hz (US TV), 47.952Hz (this which is rare but used in some movies), 48Hz (also used in the movie rare), 50Hz (UK sports) and 59.94Hz (US sports).
Next, VESA tests the display at the minimum Adaptive-Sync range of the monitor. If the monitor has an Adaptive-Sync range of 40 to 60 Hz, for example, VESA will test it at 40 Hz, even if the MediaSync display level only calls for a range as low as 48 Hz, and the Adaptive- Sync level 60Hz. If a monitor’s Adaptive-Sync range has a minimum greater than the certification requires, VESA doubles frames that are slower than the minimum.
A common cause of stutter is 3:2 pulldown, which is used to display Hollywood movies shot at 23.976Hz and results in dropped frames per second. VESA certification aims to eliminate the need for 3:2 pulldown.
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