The announcement of HDMI 2.1 changed this, though, and added support for the open Adaptive Sync format over HDMI to some new TVs. Until now, Adaptive Sync has only been supported by new Xbox Ones. This changed in October 2019 when NVIDIA added support for Adaptive Sync over HDMI to some of their existing graphics cards. This new feature works with any GeForce RTX or GeForce GTX 16-Series GPU, and requires a TV that supports Adaptive Sync (not FreeSync). NVIDIA has grouped this new feature into their existing G-SYNC Compatible certification program.
If you have an NVIDIA GTX-16 series or RTX 20-series graphics card and would like to buy, or already own, an Adaptive Sync (also known as HDMI Forum VRR) compatible TV. This will allow you to enable Adaptive Sync, even though your NVIDIA card doesn't natively support it. Enabling Adaptive Sync delivers a nearly tear-free gaming experience, which is great when the frame rate drops below your TV's native refresh rate. This is especially noticeable in graphically-intense scenes, if your graphics card can't maintain a high frame rate, or when switching out of pre-rendered cinematic cutscenes.
We test Adaptive Sync on a custom-built PC, with an EVGA RTX 2070 Super Black Edition GPU. We use NVIDIA's Pendulum G-SYNC demo to test for tearing, stuttering, screen blanking, and other artifacts. The first thing we do is disable V-SYNC, as we want to be absolutely certain that the display is adjusting its refresh rate to match the source content. We then enable G-SYNC from the pendulum demo, and, starting at the TV's native refresh rate, we gradually decrease the sliders, looking for any issues. From there, we gradually increase the sliders until we start seeing tearing or other issues. The results of both of these tests give us the effective variable refresh rate range. We repeat the test at least twice to confirm our findings.
We also playtest each TV with a few games, including Destiny 2. During our playtesting, we check for any tearing, especially in scenes with low frame rates and when the game transitions from pre-rendered cutscenes to in-game, as this sudden change in frame rate can cause excess tearing on some displays.
We use the results of this test to subjectively assign a result, based on how well the TV supports NVIDIA's Adaptive Sync implementation. The possible results are:
To use the new mode, you must have an NVIDIA 16- or 20- series graphics card. On most TVs, you'll also have to enable FreeSync or Adaptive Sync for it to work.
To enable FreeSync, you must first select "G-SYNC Compatible" from the Monitor Technology setting under NVIDIA Control Panel. Once this setting has been enabled, you should see a new option, Set up G-SYNC, appear under the Display menu. From there, you can enable G-SYNC for either full-screen mode, or both full-screen and windowed mode.
As of November 28 2019, only three TVs have received official G-SYNC Compatible certification. They are:
Although these are the only TVs that are officially supported by NVIDIA, we were also able to enable Adaptive Sync when connected to a few other TVs, including:
We will continue testing for this on all future TV reviews, and let us know in the discussions below if any updates are released that might change our results.
This test is by no means exhaustive, and your results may vary depending on the specific games you are playing, and your specific graphics card. On most TVs, some tearing can still occur, especially during rapid refresh rate changes. This could cause a few seconds of tearing when changing from pre-rendered cutscenes in games, to the in-game engine, or if the game suddenly slows down significantly.
We hope to expand this test in the future; let us know in the discussions down below if you have any suggestions on things we could check.
The addition of Adaptive Sync to NVIDIA's drivers is a welcome change and represents a significant policy shift at NVIDIA. We hope to see more TVs support Adaptive Sync.