What just happened? The Video Electronics Standards Association has announced a new certification program to certify variable refresh rate displays for jitter, flicker, response time, and more. While this won’t replace reliable third-party reviews, we hope buying a decent monitor or laptop becomes less of a hassle. .
The Video Electronics Standards Association (VESA) just announced a new certification program to make it easier for consumers to select the right Variable Refresh Rate (VRR) display. The new standard will join other standards implemented by the organization, including Displayport certifications, display mounts, and DisplayHDR.
Variable refresh rate is a technology that allows displays to change their refresh rate on the fly between a certain range, eliminating stuttering and tearing. Nvidia’s G-Sync and AMD’s FreeSync are vendor-specific VRR solutions, but VESA introduced native VRR support with Displayport version 1.2a back in 2014. GPUs from AMD, Intel and Nvidia now support this standard.
Nvidia and AMD already have proprietary VRR display certification programs, but they don’t specify which tests and display settings are involved. Let’s hope the VESA program fixes this by being more open about testing procedures and being stricter about which displays get tested.
Today, VESA is rolling out two levels with two corresponding logos that manufacturers can use if their devices pass the test. The association will not test any “overclocked” refresh rates offered by manufacturers in the OSD. All certification is done with factory default settings, which means Standard mode should have a reasonable pixel response time without unusable undershoot or overshoot.
The first certification is AdaptiveSync, and it’s mainly for gaming monitors. This requires displays to have a minimum refresh rate of up to 60Hz and a maximum of at least 144Hz. The logo will represent the maximum refresh rate supported by the display. Support for low frame rate compensation is also mandatory, which helps devices stay within the VRR range even if the frame rate falls below the minimum refresh rate.
The standard also checks displays for flicker, dropped frames, jitter, and gray-to-gray (G2G) response time, which should be less than 5ms. Doesn’t sound too impressive, given that many modern monitors advertise sub-1ms response times. However, VESA tests will be much stricter.
First, VESA will test in a tightly controlled ambient temperature of 22.5-24.5°C. Temperature constancy is important because the response time improves significantly as the temperature of the display rises. Second, VESA will only consider the average response time of 20 different G2G transitions, rather than choosing the best one. Finally, overshoot and undershoot must be below certain thresholds during all tests.
The second specification, MediaSync, belongs to a lower class and is focused on the correct operation of VRR for media playback and content creation. This requires a relatively narrow refresh rate range of at least 48-60Hz, but VESA still checks for flicker, overshoot, undershoot, and most importantly jitter.
On a non-VRR 60Hz display, watching a movie at 24 frames per second will result in even frames appearing in three refresh intervals and odd frames in two. This is called 3:2 conversion and results in jitter. MediaSync-certified displays will correct this by using frame doubling if necessary to bring the lowest frame rate up to the monitor’s refresh rate range, with jitter limited to 1ms.
It should be noted that VESA only tests and certifies Displayport capable displays such as monitors and laptops. You can learn more about testing methodology and certification here.
Credit: www.techspot.com /