Many of our favorite TVs and monitors today boast high refresh rate displays that promise smoother screen action and a sharper picture. The latest iPhone 13 Pro models can reach a refresh rate of 120 Hz, as can several Android phones from Google.
High refresh rates are also talked about a lot in games where quick response and instant on-screen updates can mean the difference between winning and failing.
What is the refresh rate?
All content on your display consists of individual stills (photos) that are displayed sequentially at very high or fast speeds. The refresh rate is measured in hertz (Hz) and it determines how often the frame can change. The 120Hz refresh rate allows you to display a new frame up to 120 times every second. The 60 Hz display can update the screen only 60 times every second. And you can guess how many times the 90Hz screen can be updated.
And what about the frame rate?
It is important to note that the potential benefit of a high screen refresh rate is limited by the frame rate of what is on the screen. With video or video game graphics this is expressed as frames per second (FPS). Movies usually go at 24 frames per second because it’s a theatrical standard, while many games can run at up to 120 frames per second.
Touch response speed?
To confuse you even more, manufacturers sometimes list the response frequency (or touch sampling rate) for touchscreen displays, which is also measured in hertz (Hz). This number refers to how often the touch screen scans at the touch of your finger. The higher the touch response speed, the faster it responds to your touch.
How the refresh rate affects your phone
A higher refresh rate allows the phone’s display to keep up with gaming action and reduces motion blur on video, but it can also make interface navigation more sensitive than on a display with a lower refresh rate. During the frantic action of the game look less picky, the video footage of the rapid sporting action looks smoother, and any jerks when scrolling a long web page are reduced. To get the full benefit of a high refresh rate, you also need a high frame rate, and ideally a match.
The cost is often battery life. More frequent image updates on the display require more battery power. Computing power is also needed to run graphics with a higher frame rate. Processors have improved significantly, but battery life is still limited on smartphones. For this reason, most phones with the highest refresh rate do not work with the highest frequency. This includes some new iPhone Pro 13 models that have an “adaptive” refresh rate of 120 Hz that increases over time, presumably when you notice it.
The higher refresh rate first came to gaming-oriented smartphones Razer Phone, but since then manufacturers such as Samsung, OnePlus and Google have introduced them to flagship devices such as the Galaxy S21 and Pixel 5 series.
What about TVs and monitors?
The benefits of a high refresh rate for a TV or monitor are almost the same as for a smartphone. The screen action should look smoother and the image may be sharper. The frame rate of the content is also important here. There are times when the frame rate does not match the refresh rate, and this can worsen TV shows and movies.
Explains the “soap opera effect”
Some TVs and monitors cope better than others with the difference between frame rate and refresh rate. Many simply reduce the refresh rate according to the frame rate, but fixed refresh rate displays should look for other ways to deal with this discrepancy.
For example, if a movie is running at 24 frames per second but the refresh rate is higher, the TV can insert extra frames to fill in the blanks. This can be relatively simple if the refresh rate is divided by the frame rate, as the TV can show multiples of a single frame. The 120Hz refresh rate, which shows content at 24 frames per second, can show each frame five times. But with a refresh rate of 60 Hz and 24 frames per second you get an uneven number of frames, which can cause a shaky, shaky effect for some viewers.