What is VRR (Variable Refresh Rate): The TV/gaming tech explained

Variable Refresh Rate, or VRR as it is commonly known, is yet another acronym in the TV world to get to grips with. But for gamers with the latest consoles, this feature could make all the difference.

A considerable part of the latest HDMI specification (that’s HDMI 2.1) focuses on gaming. It’s populated with acronyms such as ALLM (Auto Low Latency Mode), QFT (Quick Frame Transport) and HFR (High Frame Rate). Out of all of them, VRR perhaps has the biggest impact on gaming, particularly for eSports, as it helps make console and PC gameplay more responsive and fine-tunes image quality.

So what is VRR and how does it work? What are the differences between the different types, and which devices support it?

Variable Refresh Rate enables a game console or PC to send video frames as fast as it can to a display, with the screen adapting its own refresh rate in real-time to match that of the source.

So that’s the what, this is the how. A games console/PC renders a frame and sends it to the TV to display. If it fails to send the finished rendered frame for whatever reason, the console/PC will either hold the current frame or send the next frame to keep things moving. Given the frame rate output of a console can vary depending on the complexity of what it’s doing, if the process starts to chug, the result can be a rather jumbled up looking image and unfavourable response time.

In essence, what VRR does is allow the two devices to talk to each other more effectively and be in sync with one another. Issues that crop up when the devices are out of sync are lag (slower response time), judder (a stuttering visual effect) and screen tearing, in which parts of the image on screen show visible creases or ‘tears’.

By matching the refresh rate of the source device and the display, lag is reduced for faster response times; motion is smoothed out, and screen tearing is reduced – if not outright eliminated – as the console/PC will wait before it sends the next frame and the display will adapt to match it. The result is better image quality, and a smoother, more consistent performance.

As always seems to be the case, they are competing formats vying for supremacy.

There is the ‘standard’ VRR delivered over HDMI, as well as VESA’s Adaptive Sync technology for DisplayPort compatible monitors. But it’s really a battle between AMD and NVidia over their VRR implementations in FreeSync and G-Sync, respectively.

They both aim to do the same thing, which is to reduce tearing, lag and stuttering, and both companies offer tiers of VRR with different features.

AMD

AMD FreeSync, AMD FreeSync Premium, AMD FreeSync Premium Pro
Image: AMD
  • AMD FreeSync – the entry-level version reduces tearing and latency.
  • AMD FreeSync Premium – supports 120Hz at 1080p resolution and above, as well as reducing latency and including support for low framerate compensation (LFC), which allows FreeSync to continue working when the frame rate falls beneath the display’s minimum refresh rate. This is the version supported by most compatible TVs.
  • AMD FreeSync Premium Pro – supports everything mentioned above but also adds HDR support for improved tone-mapping and lower latency in both SDR and HDR games. Samsung’s Neo QLED TVs are the first to support this version.

Nvidia

logo for Nvidia G-Sync VRR
  • G-Sync compatible – the entry-level version doesn’t require the use of Nvidia graphics cards/processor, but serves as a stamp of approval that a display will provide a ‘basic’ variable refresh rate performance, as well as tear-free and stutter-free visuals.
  • G-Sync – the version currently most supported by TVs. This provides a full refresh rate performance where supported (up to 120Hz).
  • G-Sync Ultimate – includes everything mentioned above and brings in HDR support, improved colour performance and “ultra low” latency.

At the moment VRR support is more often found on premium sets, but it is beginning to appear on more affordable models.

On the PC side there’s a wide number of desktops, laptops and monitors going back several years that support AMD FreeSync or Nvidia G-Sync VRR solutions. You can find out which ones by heading to AMD’s and Nvidia’s respective sites.

For games consoles, Microsoft supports AMD FreeSync across its console family, but on the One X (discontinued) and One S support is for 40Hz – 60Hz refresh rates.

The Series S and Series X support HDMI 2.1, and feature more advanced levels of AMD FreeSync with refresh rates up to 120Hz. FreeSync on Xbox consoles does need to be enabled in the dashboard settings as it does not automatically switch on even when connected to a compatible FreeSync display.

The PS4 does not support VRR but the PS5 can support the feature through its HDMI 2.1 port. However, Sony hasn’t activated the feature yet. They appear to be waiting for more 4K/120Hz TVs to hit the market.

You will, of course, need an Ultra High Speed HDMI 2.1 cable, as well as a display that supports VRR to complete the set. Here’s a list of TVs we’ve reviewed that support VRR.

AMD FreeSync

(All TVs listed support Freesync Premium unless stated otherwise)

Nvidia G-Sync

(Samsung TVs are known to work with G-Sync, but have not been officially certified by Nvidia)

Panasonic’s 2021 TV range will factor in support for HDMI 2.1 and AMD FreeSync Premium on select models, too. Sony TVs from 2021 and 2020 have been pencilled in to receive an update to enable VRR over HDMI, but there’s no confirmation as to when the update will appear.

Dolby Vision for Gaming will be supported on the Xbox Series X, and the LG C1 and G1 OLED TVs have received a firmware update that will enable 4K/120Hz in Dolby Vision HDR.

If you’re a gamer who plays multiplayer, sports and fast-twitch games, then having VRR will add to the experience.

The benefit is reduced latency times, better image quality and less screen tearing. With games that support 4K/120Hz, the promise is a very slick and responsive gaming experience. If you’re someone who plays adventure games or games that don’t require as fast a response, then it’s not as vital.

If you have a TV that supports more advanced VRR solutions, there’s also the benefit of better HDR tone-mapping; so contrast, luminance and detail in darker areas will be improved.

It is worth having a TV that supports VRR, but you’ll also need a supported console, HDMI cable and requisite games to experience it to the fullest. At the moment the ecosystem for VRR is still in its early phase so it isn’t as widespread, yet.

The post What is VRR (Variable Refresh Rate): The TV/gaming tech explained appeared first on Trusted Reviews.



from https://ift.tt/2T4uOFq

No comments:

Post a Comment