What is the refresh rate?
The refresh rate, in its essence, indicates the number of images refreshed on the screen per second. The higher this number, the smoother the image on the screen. The refresh rate is expressed in Hz (Hertz) units, which clearly means that it is basically the frequency of changing images on the screen.
To understand why refresh rate is important, it is first necessary to understand the concept of refresh per second. A digital panel, either LCD or AMOLED, works by firing up pixels. The movement on the display is considered a change in the color of the pixels firing at any time. This refresh rate is actually the number of times a phone sends a signal to pixels. This is how a screen displays an image. It is similar to the famous Mexican wave. The movement is seen only when people stand down, followed by the next group.
This is all well and dandy unless a screen is only displaying still images. But what happens to videos and other moving images, such as rendered games?
It is also important to understand here the concept of frames per second. Similar to the refresh rate, it refers to the number of images sent to the screen. For example, videos are typically recorded at 60 frames per second. This means that the display on which this video is shown must have a refresh rate of at least 60 Hz so that each frame can be sent to the display. This ensures the perception of a smooth image.
The most common refresh rate in modern phones is exactly 60 Hz. Sixty refreshes per second are sufficient to ensure smooth transitions, and for the human eye to not really see these refreshes as they are happening too quickly.
Technology, as we know, however, is in progress. Camera sensors have become very capable, while smartphone games are becoming more and more graphically in-demand. In this blog, we’ll use video taken by smartphone cameras as an example to explain why companies are increasing their screen refresh rates.
Why is it important?
Today’s cameras are capable of recording slow motion videos. These videos are recorded at 120 fps, 240 fps or even 960 fps. The question arises how to display more frames per second on the screen when the refresh rate is only 60 Hz? Slow-motion is realized by “stretching” the duration of the video to match each frame recorded by a camera on two refreshes of the screen. This way we can watch slow-motion videos at a fairly slow rate. This can be improved, however, by once again increasing the display’s refresh rate so that a 1: 1 ratio – 1 frame to 1 screen can be refreshed.
This is what the performance makers have tried to do! It is now becoming more and more common for phones with 90 Hz or even 120 Hz refresh rates to be displayed.
displays 90 Hz
As we said earlier, the refresh rate makes a huge difference between gaming and video display. It is no wonder that these displays are applicable in most gaming phones, but some more mainstream ones have also implemented them. Take OnePlus 7 Pro for example. Its display has a refresh rate of 90 Hz, and virtually all content looks much smoother and better than a 60 Hz display. Obviously, this difference can only be seen when the two displays are directly compared, however, it is clear that the 90 Hz display only reproduces the content more thoroughly. Here is our review of the OnePlus 7 Pro, where you can learn more about this phenomenal phone and its performance.
↑ 120 Hz Displays
OnePlus has further increased their refresh rate to the flagship phone 90 Hz, but ASUS recently announced its new gaming flagship, the ROG Phone 2. The display of this new phone will feature a 120 Hz display, meaning it will be fully capable of displaying a truly smooth 120 fps video or game render. In gaming, this is very important because every millisecond can be significant.
A common question among smartphone fans is whether the refresh rates above 60 Hz should also have a place in the market. We have already stated that a naked eye cannot be seen beyond 60 Hz. An argument should be made for some niche uses, such as sporadic video editing on phones, or competitive smartphone gaming that is on the rise. Overall, 60 Hz displays are sufficient for an average user. High refresh rates are a good feature, but they are certainly not necessary because they are not really sufficient to justify the price difference that they produce.