Adaptive refresh rate: why does a screen change its hertz?
A scrolling feed benefits from frequent screen updates; a still page of text does not need the same pace or energy use. Adaptive refresh rate lets a device adjust its display to the task, increasing the rate for motion and reducing it when appropriate.
What changes on the screen
Refresh rate is measured in hertz: 60 Hz means up to 60 screen refreshes per second, while 120 Hz means up to 120. An adaptive display automatically chooses a rate within its supported range. It may use discrete steps: “up to 120 Hz” promises neither every intermediate value nor constant 120 Hz.
Benefit one: smoother motion
With enough frames available, scrolling, gestures and animations look smoother. The interval between refreshes at 120 Hz is about 8.3 milliseconds rather than 16.7 at 60 Hz. This allows an earlier opportunity to show a new frame, though total response latency also depends on touch sensing, the app and input processing.
Benefit two: fewer unnecessary refreshes
When an image barely changes, a high refresh rate can be unnecessary. Lowering it can save energy compared with keeping the rate high. Adaptive 120 Hz does not guarantee longer battery life than every 60 Hz display: brightness, panel design, apps and battery capacity all matter. There is no universal saving percentage.
Video still depends on its original frames
A 24 FPS video does not become 120 FPS footage merely because of the display. A refresh rate that is a multiple of the video frame rate helps present frames evenly: for example, 48 Hz for 24 FPS. A compatible Mac lets you select this manually. Automatic matching depends on the device and app.
ProMotion and Always-On Display
ProMotion is Apple’s name for its adaptive refresh technology. Compatible iPhones, iPad Pro models and MacBook Pro models support it, but their ranges differ. For example, iPhone 13 Pro supports 10–120 Hz, while iPhone 14 Pro can drop to 1 Hz for Always-On Display. This helps show the clock and other information using less energy. ProMotion support alone does not imply Always-On Display support.
Why a game might still run at 60 FPS
Hertz describe display refreshes; FPS describes frames produced by a game. Reaching 120 FPS requires game support, suitable settings and enough performance. Heat and power settings also matter: Low Power Mode limits refresh rate to a maximum of 60 Hz on iPhones and iPads with ProMotion. An adaptive display does not speed up the processor.
Who benefits, and what to compare
The benefit is easier to notice if you scroll websites often, work with animation or play supported games. A high rate matters less for reading a still page. Compare maximum refresh rate, adaptive support and the supported range separately: two displays labelled “120 Hz” can behave differently. In Difluma, check these rows in the specifications of your selected devices.