Variable refresh rate
A variable refresh rate (VRR) is the general term for a dynamic display refresh rate that can continuously and seamlessly vary on the fly, on displays that support variable refresh rate technologies.
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 variable refresh rate range (VRR range). The refresh rate can continuously vary seamlessly anywhere within this range.
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 (stutter) or a mixture of the old frame and the completed part of the new frame is shown (tearing). Conversely, if the frame is ready before the interval arrives, then it won't be shown until that interval arrives. A major purpose of variable refresh rates is the elimination of stutters and tearing by keeping refresh rates in sync with a varying frame rate from a video game. This makes display motion more smooth despite a varying frame rate.
More recently, since the 2010s decade, 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 display technologies include several industry standards and proprietary standards:
- AMD FreeSync
- Nvidia G-Sync
- VESA Adaptive-Sync press release
- HDMI 2.1 Variable Refresh Rate (VRR)
- Apple ProMotion
- Qualcomm Q-Sync
- G-SYNC, Chief Blur Buster in. "Preview of NVIDIA G-SYNC, Part #1 (Fluidity)". Blur Busters.
- Soomro, Adeel (January 5, 2017). "HDMI 2.1 brings 8K, 10K resolution and variable refresh rates".
- "G-Sync vs. FreeSync: Adaptive sync gaming monitors explained". PCWorld. September 7, 2018.
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- "Adaptive control of display refresh rate based on video frame rate and power efficiency".
- NVIDIA Newsroom. "NVIDIA Supersizes PC Gaming with New Breed of Big Format Gaming Displays | NVIDIA Newsroom". nvidianews.nvidia.com. Retrieved 6 January 2021.
- "Variable refresh rate for stroke CRT displays".
- Siddiqui, Aamir (12 August 2020). "The Galaxy Note 20 Ultra is the first phone with Samsung's new VRR OLED display". xda-developers. Retrieved 12 August 2020.