Every year Apple adds one or two features in its flagship iPhone model, which, even if not new, has the capability to move the industry as a whole. This year was no different with the recent iPhone 13 Pro range offering a 120Hz high-refresh-rate display which Apple is calling ProMotion. Top-end Android phones from Samsung and others have had this feature for a couple of years now, but since Apple is making it easier for developers to benefit from this feature, it is going to get more adoption in the industry.
Here is what adaptive refresh rate means, how it changes user interaction with the smartphone.
What is refresh rate?
Whether it is a TV, a PC monitor, or a smartphone, all devices constantly change the pixels they display to project the appearance of motion. Simply put, refresh rate means how many times the image on a screen can be updated or “refreshed” every second – much faster than your eye can detect. Refresh rate is measured in Hertz (Hz). For example, your HD TV at home has a 60Hz refresh rate like the iPhone 12 series. At 60Hz TV can refresh the screen 60 times per second, while at 120Hz on the iPhone 13 Pro can refresh the screen 120 times per second. The higher the refresh rate, the more times per second the screen is refreshing its pixels.
Refresh rate vs frame rate
While the refresh rate is the number of times per second an image is refreshed or flashed on the screen, the frame rate is the rate at which frames appear in a display and form moving imagery. When a video is displayed on a screen, the speed at which it is played is also known as the frame rate. Experts believe the human eye can see between 30 and 60 frames per second. Movies are shot and played at 24 frames-per-second rate. To be clear: there are 24 frames in 1 second of video. This is the standard frame rate for videos.
If you are shooting a video using a smartphone camera, 30 frames per second (FPS) is almost the standard now. Games, meanwhile, are created with up to 120 FPS. For the best visual experience, refresh rates and frame rates have to work together. For example, a mobile game running at 120 frames per second should look smooth on a 120Hz display when compared to the same game running at 60 fps on a 60Hz display.
So, what is an adaptive refresh rate?
When the display has an adaptive refresh rate, like with the ProMotion display on the new iPhone 13 Pro series, the refresh rate changes from 10Hz to 120Hz depending on the content being played — some Samsung phones offer between 48Hz and 120Hz. So a static website will be played at 10Hz refresh rate and a game at 120Hz refresh rate. This means there is little chance of under delivering or over delivering refresh rate. Apple is not giving users the option to set a default refresh rate on the phones as some Android phones do. But developers will have the ability to code in such a way that they can set specific refresh rates for different aspects of their app.
When does the refresh rate matter?
Faster refresh rates are usually better at handling motion, especially when watching action movies, playing video games, or scrolling through your Twitter timeline. If you are into hardcore mobile gaming, the high-refresh display makes a huge difference.
Would you see a drastic change in the way you use your smartphone? Absolutely not… 60Hz displays are good enough for average consumers, but companies like Apple, Samsung and OnePlus believe the 120Hz display is a “pro” feature, aimed at a specific audience. This is why the iPhone 13 and iPhone 13 mini are limited to a 60Hz display while the top-end iPhone 13 Pro series has a display that can go up to 120Hz.
Does a high-refresh rate impact gaming?
Yes and No. If you play a casual game like Super Mario Run or Subway Surfers on the iPhone 13 Pro Max it does not really take advantage of the 120Hz “ProMotion” display. But if you play Alto’s Odyssey or Dead Trigger 2 on the iPhone 13 Pro Max, those games will benefit from using the 120Hz display. You will actually notice that this results in improved motion resolution, reduced ghosting, and better responsiveness. A lot of what adaptive displays offer is driven by the powerful processors and low-temperature polycrystalline oxide (LTPO) displays that are making their way to phones these days, even more so when the system has to decide what refresh rate to show when.
…but a high-refresh rate could impact the battery life
One other reason for adding an adaptive display in phones that can offer 120Hz display, is the impact higher refresh rates have on battery life. So the adaptive refresh rate in the new iPhones and phones like the Samsung Galaxy S21 Ultra are designed to save the phone’s battery life by boosting refresh rates only when they’re really needed.
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