{{short description|Dynamic display refresh rate that can continuously and seamlessly vary on the fly}} '''Variable refresh rate''' ('''VRR''') refers to a dynamic display that can continuously and seamlessly change its refresh rate without user input. A display supporting a variable refresh rate usually supports a specific range of refresh rates (e.g. 30 Hertz through 144 Hertz). This is called the VRR range. The refresh rate can continuously vary seamlessly anywhere within this range.<ref>{{Cite web|url=https://blurbusters.com/gsync/preview/|title=Preview of NVIDIA G-SYNC, Part #1 (Fluidity)|first=Chief Blur Buster in|last=G-SYNC|website=Blur Busters}}</ref>

== Purpose ==

On displays with a fixed refresh rate, a frame can only be shown on the screen at specific intervals, evenly spaced apart. If a new frame is not ready when that interval arrives, then the old frame is held on screen until the next interval (judder) or a mixture of the old frame and the completed part of the new frame is shown simultaneously (tearing). Conversely, if the frame is ready before the interval arrives, then it won't be shown until that interval arrives.

Variable refresh rates eliminate these issues by matching the refresh rates of a display to be in sync with the frame rate from a video input, making the display motion more smooth.<ref>{{Cite web|url=https://displaylag.com/hdmi-2-1-brings-8k-10k-resolution-variable-refresh-rates/|title=HDMI 2.1 brings 8K, 10K resolution and variable refresh rates|first=Adeel|last=Soomro|date=January 5, 2017}}</ref><ref>{{Cite web|url=https://www.pcworld.com/article/2974781/g-sync-vs-freesync-faq-how-variable-refresh-rate-displays-make-pc-games-super-smooth.html|title=G-Sync vs. FreeSync: Adaptive sync gaming monitors explained|date=September 7, 2018|website=PCWorld}}</ref> Although VRR is strongly associated with video games due to such content having unpredictable, discontinuous frame rates that would benefit from the technology, it is also useful for media whose frame rate is fixed and known in advance, such as film and video. Being able to sync the refresh rate with industry standard framerates (24, 25, 29.97, 30, 50, 59.94, and 60 FPS), it again helps to eliminate screen tearing.<ref>{{Cite web|website = Google Patents| access-date = November 21, 2023| url=https://patents.google.com/patent/US9589540B2/en|title=Adaptive control of display refresh rate based on video frame rate and power efficiency}}</ref><ref name="nvidia">{{cite press release |url=https://nvidianews.nvidia.com/news/nvidia-supersizes-pc-gaming-with-new-breed-of-big-format-gaming-displays |author=<!-- not stated --> |title=NVIDIA Supersizes PC Gaming with New Breed of Big Format Gaming Displays |publisher=NVIDIA |date=7 January 2018 |access-date=10 February 2026}}</ref> VRR also has use in power management, by temporarily lowering the refresh rate of a display during instances when there is little movement on the screen to save power.<ref>{{Cite web|url=https://patents.google.com/patent/US7844842B2/en|title=Variable refresh rate for power management}}</ref>

== History ==

Vector displays had a variable refresh rate on their cathode-ray tube (CRT), depending on the number of vectors on the screen, since more vectors took more time to draw on their screen.<ref>{{Cite web|url=https://patents.google.com/patent/US4511892A/en|title=Variable refresh rate for stroke CRT displays}}</ref>

Since the 2010s, raster displays gained several industry standards for variable refresh rates. Historically, there was only a limited selection of fixed refresh rates for common display modes.

Variable refresh rate was first incorporated into a display interface standard by VESA, which included Adaptive-Sync as a optional feature in the DisplayPort specification beginning in 2009. However, the feature was not formally introduced until the release of DisplayPort version 1.2a in 2014.<ref name=":0" />

The first commercial implementation of VRR technology was Nvidia's G-Sync which launched in 2014.<ref>{{Cite web |last=Baker |first=Simon |date=2019-04-18 |title=Variable Refresh Rates - G-sync and FreeSync |url=https://tftcentral.co.uk/articles/variable_refresh |access-date=2026-04-07 |website=TFTCentral |language=en-US}}</ref> The first display to support G-Sync was the ASUS VG248QE, which required users to purchase a separate $199 DIY upgrade kit to enable functionality.<ref>{{Cite web |date=2014-01-17 |title=NVIDIA G-Sync DIY Kit For ASUS VG248QE Monitor Now Available for $199 - PC Perspective |url=https://pcper.com/2014/01/nvidia-g-sync-diy-kit-for-asus-vg248qe-monitor-now-available-for-199/ |access-date=2026-04-07 |website=pcper.com |language=en-US}}</ref>

== Implementations ==

Variable refresh rate display technologies include several industry standards and proprietary standards:

* AMD FreeSync * Nvidia G-Sync * DisplayPort 1.2a's optional ''Adaptive-Sync'' feature<ref name=":0">{{cite press release |author=<!--Not stated--> |title=VESA® Adds 'Adaptive-Sync' to Popular DisplayPort™ Video Standard |url=https://vesa.org/featured-articles/vesa-adds-adaptive-sync-to-popular-displayport-video-standard |location=Newark, California |publisher=VESA |date=12 May 2014 |access-date=2024-04-10}}</ref> * HDMI 2.1 Variable Refresh Rate (VRR)<ref>{{cite web |url=https://www.hdmi.org/spec21sub/variablerefreshrate |title=Variable Refresh Rate (VRR) |website=hdmi.org |publisher=HDMI® Licensing Administrator, Inc. |access-date=2024-04-09}}</ref> * [https://www.gsmarena.com/understanding_apples_promotion_display_on_the_new_ipad_pro-news-25446.php Apple ProMotion] *[https://www.qualcomm.com/news/onq/2017/01/24/snapdragon-835-powering-immersive-vr-and-ar-experiences-youve-been-waiting Qualcomm Q-Sync]

==References== {{Reflist}}

== External links ==

* [https://www.testufo.com/vrr TestUFO Animation: Variable Refresh Rate Simulation]

Category:Graphics hardware Category:Temporal rates