Refresh rate: what is it, what does it do and why is it measured in Hz

No, it’s not about how often you put your drink in your mouth during a night out. The refresh rate – or at least what we will talk about on this occasion – is one of the many characteristics of digital screens, but in recent times, and especially in the case of mobile phones, it has become one of the most most important protagonists of the visual experience.

Until a few years ago, the most relevant aspect of screens was their size —measured in inches—, their resolution —measured in pixels but also in other standards, such as FullHD or 4K— and the technology with which they are made. After the reign of the LCD, it is the OLED screens (or organic light-emitting diodes) which take the throne in this section, which begin to predominate in notebooksportable consoles, portable and cell phones.

But among these three characteristics, has slipped the cadence, the frequency or the refresh rate of the screens, which is becoming more and more important in the announcements of the manufacturers. It is measured in hertz (Hz) and here we explain what it is, its relevance and how it affects the performance of our equipment.

Before knowing what the refresh rate is, it is necessary to know what is hidden behind the operation of a screen. Although we think they are always on when we look at them, the truth is that they constantly turn on and off, in very rapid flashes that the human eye is not able to perceive.

This is the phenomenon known as “persistence of vision” in which the images stay in the brain for a fraction of a second longer, allowing to generate this feeling of movement and continuity, as it happens in cinema and stop-motion animation.

So every time a screen — be it a computer, phone, tablet, or TV — shows a new image, it turns on and off — or refreshes — at a very high frequency. What size? This is what determines the refresh rate, which is measured in hertz (Hz).

The hertz is a measurement of frequency, formerly called “cycle per second (cps)”, but since 1960 it bears this name, in honor of the German physicist Heinrich Rodolphe Hertz , discoverer of electromagnetic waves. It is the unit that measures the cycle of repetitions of an event in one second.

The formula, if we get mathematical, is 1 Hz=1/s. This means that something with a frequency of 1 Hz happens once per second. Therefore, a screen with a refresh rate of 60 Hz – the standard until recently in mobile phones – turns on and off 60 times per second.

In the early years of cinema, the speed at which movies were recorded and projected was 16 frames per second, or whatever, with a refresh rate of 16 Hz. Later it increased to 24 frames, the standard used for this. daytime.

But with electronic devices it is different, because the information we see is not only audiovisual: in addition to videos, there is the movement that the screen simulates when we browse social networks, when we minimize or open a application, when we play a video game, etc.

A few years ago hardly anyone talked about hertz or refresh rate on cellphones since they all had the same: 60Hz. But when cellphones started to adapt to the demands of the world player, which demanded more information on the screen and at very high speeds, the prices began to climb and, without explaining their function very well, they became a plus in the promotion of the teams. Today, mid-range models have 90Hz refresh rates, and some high-end ones are already basking in 120Hz.

To sum up: a higher refresh rate is able to update the images on the screen more quickly and, thus, give more fluidity to the movement that we see there. Videos, animations, video games, and almost any other interaction will feel much more natural, with no interruptions or swipes. When the refresh rate increases, the sharpness of images also increases.

These are the advantages, which will be perceived mainly by those who use their phone to play video games or who use it intensively to view and publish on social networks, who have more and more information, videos and movements on them. Especially for those who have equipment with 120 Hz, twice the frequency of the standard.

But the downside is that this increased rate forces the processor to work harder – it has to work harder by turning the screen on and off more times – which will eventually heat up the phone and drain the battery faster. That’s why almost all mobiles that have these higher refresh rates have the option to activate or deactivate it, so as not to consume too much energy.

Because the truth is that as long as the phone is idle, locked, or we only have it to make calls or send or check messages, keeping 120 or 140 Hz active is a waste. It is however not if we watch videos or use video games, where the difference will be noticeable and the experience very pleasant.

Of course, just because the display has a 120Hz refresh rate doesn’t mean it consumes twice as much power as a 60Hz display. Switching on and off are also twice as short, so the increase in energy consumption is not directly proportional.

As we said, new models are promoted with their refresh rates, so if you have a recent cell phone, it’s not hard to google and find out how often the screen is updated.

But in models with more years this information is not so easy to find. In this case, the easiest way is to download applications, always on Android, responsible for providing us with this data and others on our equipment. The ones we mention are free and reliable, although with some ads that you have to put up with. One thing for another.

The first of these applications is DevCheck developped by fl2 , with which we can discover all the features and hardware specifications of our mobile phone: what are its components, in what ranges it works, what capacity the processor and battery have, among others. Very useful to really know what we have in our hands, such as what is the refresh rate.

When installing the app, all you have to do is go to the “Hardware” tab and scroll down until you find the graphics and screen information. Under the name “Frame frequency” appears what we are looking for: the hertz with which the mobile phone is refreshed.

Another free option is screen information , an application dedicated exclusively to providing information regarding the screen of our mobile phone. It has over 100,000 downloads and an average rating of 5 stars, which it achieves because it only delivers what it promises: delivering cellphone dimensions, density and refresh rate. Quick and easy.

In the past year, we have tested and reviewed many mobile phone models with interesting refresh rates. The 60 Hz standard we were talking about at the start is no longer so: mid-range equipment —focused on the general public, at a price of around 400,000 pesos— already arrives at 90 Hz, while the top of the range are all have 120hz.

In the first case, an interesting model that we tested in 2022 was the Vivo V25, whose front is AMOLED, measures 6.56 inches and has FullHD+ resolution. Its refresh rate is 90 Hz, not the highest but enough to enjoy social networks and the usual Internet content without problems. Our specialist Alejandro Alaluf defined the V25 as “a good option for young people or anyone who wants to have a mobile phone that stands out when taken out of their pocket or purse, as well as a set of cameras reliable all-terrain”.

With a higher rate we have the POCO F4 GT, a smartphone designed specifically for users playerwith buttons on the sides to use them controller and a whole configuration that facilitates the performance of the most robust video games. Its refresh rate reaches 120 Hz, ideal for supporting all kinds of games, videos and content of the highest resolution and demand. According to Alaluf, due to its price-performance ratio, the F4 GT is the “best phone player of the year”.

Another model that passed our tests and left us very satisfied is the Xiaomi 12T Pro, the smartphone spearhead of the Chinese brand, a top of the range with a very reasonable price and a variable refresh rate that reaches 120 Hz. In other words, the phone adapts to different requirements and when it has to undergo a video game or a high resolution content, it increases the hertz of your AMOLED display. These, in turn, decrease when use does not force them to be so high.

Surprisingly, the mobile phone with the highest refresh rate that we tested this year was the Motorola Edge 30 Fusion, a mid-range capable of rubbing shoulders with the most premium models on the market: it weighs only 175 grams, has a Interesting Snapdragon 888+ and a 6.55-inch pOLED display that refreshes, reads well, at 140Hz. Its 4,400mAh battery might not be the most secure in the business, but at least good performance and image quality are assured. And for less than 600 thousand pesos.

*Prices for products in this item are updated as of December 30, 2022. Values ​​and availability may change.