The iPhone 13 has a high screen refresh, is it stable?

From simple to extravagant easy, from extravagant to simple. This principle still applies in the field of consumer electronics.

The screen technology of smartphones has undergone innovations in multiple dimensions such as resolution, material, and refresh rate. In the past, we thought that the screen resolution and refresh rate were sufficient. After all, it is difficult to distinguish the difference between them, such as the difference between 90 points and 95 points.

But the human eye is extremely adaptable, and to bring a better experience, screen technology must continue to move forward. Nowadays, the screen can be said to be the most important indicator for judging the performance of smartphones. It is said that the eyes are the windows of the soul. For the smartphone, the screen can also be said to be a window, and it is also a floor-to-ceiling window that can enhance the interactive experience.

Since the OnePlus 7 Pro led the high refresh rate screens in 2019, nowadays, from flagships to thousands of yuan phones, all are equipped with high refresh rate screens. On the other hand, the iPhone in the iOS world still sticks to the 60Hz screen, meditation and Buddhism.

As a former iPhone user, I had a very Buddhist mentality before I touched the high refresh screen. I claim that 60Hz is enough, and with the creamy transition of iOS, it can be comparable to 90Hz. But until one day, I used the Android high-brush flagship, and everything changed.

Under the high refresh rate screen, I feel the real silky smoothness. When I use the iPhone again, iOS behaves like a friend who is awkward with you all the time, and a jerky and lagging feeling emerges spontaneously. At this time, I stopped meditation and joined the team denouncing that the iPhone would no longer be bought without having to swipe the screen.

Since its development, to be honest, the iPhone is no longer a rival of several other Android phones. The gap between them has been narrowing, and has even been surpassed in some features. A high refresh rate screen is one.

The optimal solution for high refresh

As we all know, Apple's products are not the first in the industry to "eat crabs", such as Touch ID, dual-camera, facial recognition, and OLED screens. But once Apple launches mass-produced products, its hardware standards and software tuning will be the industry leader. For high refresh rate screens, Apple should be looking for the current "optimal solution."

This optimal solution has actually appeared in Apple products, and there is also a corresponding mass-produced product in the Android camp, which is the LTPO OLED screen (hereinafter referred to as LTPO).

The full name of LTPO technology is Low Temperature Polycrystalline Oxide, which is translated into "Low Temperature Polycrystalline Oxide" in Chinese. What it is called and how it is formed is actually not important to us consumers. After all, reading and recitation does not necessarily score points in the exam.

▲ Apple Watch Series 5 supports always display.

The biggest advantage of LTPO technology is that it supports adaptive adjustment of the refresh rate of the OLED screen, which can theoretically be as low as 1Hz, thereby reducing the high energy consumption of the display that has always been high refresh. Apple Watch Series 5 uses the LTPO technology screen. In the case of "always display", it can still have the same battery life as Apple Watch Series 4, and the effect is still very obvious.

Apple Watch is actually like Apple's test field. Any new technology will be tested on Apple Watch first. LTPO is one item, as is the previous AMOLED screen. It stands to reason that LTPO screen technology has achieved good results on Apple Watch Series 5, and the iPhone should also be used. It's just that the LTPO screen has very high technical requirements, and mass production is difficult. A few years ago, it could only be used on the Apple Watch with a small screen size.

Later, Samsung improved its technology to increase production capacity and used a new generation of LTPO technology screens on its flagship Galaxy Note 20, which is also the first step for LTPO technology to become popular. Now, the latest LTPO technology screen appears on the OPPO Find X3 series and OnePlus 9 Pro.

Compared with Samsung’s own flagship products, Oga has developed the potential of LTPO technology screens through cooperation with Samsung, which can achieve a minimum refresh rate of 1Hz. And in daily life, the frequency conversion of 1Hz~120Hz 120 gears can be achieved, and with the corresponding software algorithm optimization, there will be a 50% reduction in power consumption in theory.

Two advantages and one challenge of LTPO screens

Theory belongs to theory, let's take a look at the final effect. (Find X3 Pro is taken as an example here, and it has been upgraded to the latest firmware.)

In fact, before and after the upgrade, there is no obvious and perceptual change in the system experience. But on the first day, I paid special attention to the battery life. After the upgrade, the battery life of Find X3 Pro has been significantly improved. The same way of use, after 24 hours, there will still be about 45% of the battery (usually about 20%) ), if you concentrate on your work, you should be able to get off work.

In addition, in order to save power, the high frame rate mode of Find X3 Pro has intelligent dynamic frame rate adjustment. The use of these days has also made me feel some ways and some problems.

"Smart dynamic frame rate" is mostly divided according to application scenarios. For example, when staying on the desktop and the browser, there will be an ultra-low refresh rate of 1Hz. When watching video apps such as station B and oil pipes, the frame rate may be It will be tuned to 24Hz, 30Hz, and in different games, it will come to 60Hz, 90Hz and 120Hz.

▲ There will be obvious frame rate changes when switching to station B. (The display screen frame rate in the developer options is actually not accurate on the LTPO screen. It just shows the current highest refresh rate, but it is enough to explain the problem.)

But in reality, the "frequency conversion" strategy of the Find X3 Pro screen is a little bit "crude". The most obvious is to switch to video applications (Station B, Oil Pipe, Tencent, etc.). The frame rate of the screen will be locked at 60Hz. When you jump directly from 120Hz to 60Hz, you will have a more obvious perception.

To this end, I also specially verified the situation of one plus 9 Pro. After entering the video App, the frame rate is maintained at 120Hz, which is as smooth as before. Only after the full-screen video, the screen frame rate will be adjusted to 60Hz. Relatively speaking, in terms of video App, the intelligent dynamic frame rate adjustment of OnePlus 9 Pro is more intuitive. However, Find X3 Pro's screen dynamic frame rate adjustment has become more user-friendly, which is just an OTA matter.

In order to fully utilize the potential of the LTPO technology screen, in addition to the excellent hardware, more detailed optimization of the software is needed. It can even be said that without reducing the experience, the optimization of the software ecology plays a decisive role.

In addition to dynamic refresh, full scenes to save power for high refresh, LTPO technology screen has another advantage, in short, its stepless frequency conversion feature can make the game operation more handy, and the delay is also lower.

Simply put, in different scenes in the game, the GPU rendering time is also different. When encountering many diffuse reflections and complex scenes, the GPU rendering time will be very long. In order to ensure that the screen does not tear and has low control and low latency, the PC G-Sync and Free-Sync technologies have emerged, which can control the display refresh delay to be consistent with the GPU output delay, and avoid stuttering caused by dropped frames.

In reality, this requires the dual conditions of a G-Sync chip and a display that supports G-Sync technology, and it is almost the standard configuration of an e-sports display, in order to lower the control delay and be more comfortable. (For the introduction of Free-Sync implementation method on Android, here is only a very simple explanation. Friends who want to know more about it, can refer to the three columns of Zhihu@苍浪之水, which have more professional and detailed technologies. explain.)

In fact, on mobile devices such as smartphones, Qualcomm has introduced Q-Sync with reference to the concept of Free-Sync. The mechanism of action between them is very similar, and they will be dynamic according to the rendering time of each frame. Adjust the synthesis time of each frame.

However, before the LTPO technology screen supports stepless frequency conversion screens, Qualcomm's Q-Sync is difficult to land, or it is difficult to take advantage of it. Previously, the screen refresh rate of smartphones has only a few changes (60Hz, 90Hz, 120Hz), it is difficult to match the synthesis time of different frames, and frequent switching may cause screen blur.

OPPO and OnePlus introduced Q-Sync under the LTPO technology screen on the new flagship, and at the same time they developed O-Sync, which they call overclocking response. In addition to adapting to the synthesis time of different frames, it also speeds up the synchronization frequency between the screen and the processor to 360Hz (if the 60Hz refresh is used as the benchmark, it is increased by 6 times), which can render the chip faster The picture is fed into the screen. When you touch it, you will have a faster response than the original device. This advantage is not obvious in normal applications, but it will have a more hands-on control in the game.

At present, LTPO technology screens generally have these two advantages. In fact, they all support 120-speed frequency conversion with a refresh rate of 1Hz~120Hz. It can adjust the refresh rate according to different scenarios to achieve the purpose of saving power. In the game, you can also perform more flexible rendering based on a faster synchronization frequency to achieve low latency.

But judging from the current products, there are good places and some places where optimization is not enough. The good part is that it saves electricity and makes the control more user-friendly. Where optimization is not enough, it is still in the variable frequency strategy of different software and different scenarios. This is also a point that requires manufacturers to continue to think and optimize.

Where is Apple's advantage?

And the new iPhone that will use the LTPO technology screen will naturally have these advantages and disadvantages from now on.

▲ The iPhone 12 series is far from perfection, it seems to be one piece of high refresh. Picture from: the Verge

It can reduce the battery life pressure brought by the high refresh rate screen to the iPhone (which may be similar to the current iPhone 12 series battery life), and how to change the screen refresh rate according to the scene and software is still a challenge. As for the control with lower latency in the game, it can almost make the iPhone the best "gaming phone" again.

The improvement brought by the high refresh rate can actually refer to the iPad Pro with ProMotion screen. Here we will talk about the frequency conversion strategy. The biggest difference between iPhone and Android is the right to speak in the third-party software ecosystem. Apple has a strong appeal to the iOS ecosystem, which is a major advantage in optimizing the frequency conversion strategy.

It can draw a rule frame, and then allow developers to optimize different refresh rate calling strategies in their App according to the rules. For example, in video apps such as YouTube and Station B, before entering the horizontal screen and maximizing the video, you can Use the highest refresh rate, and after full screen, it can be consistent with the video frame rate (such as 24Hz, 30Hz, 60Hz, etc.). In this way, there is no need to optimize all the App ecology and scene rules by yourself.

This is like the dark mode that was launched at the time. Android and iOS adopted completely different strategies. Androids have pre-built options that can be darkened globally, and can force applications to switch to dark colors according to the rules, while iOS allows development The person optimizes and completes by himself. Different right to speak to the ecology has led to different ways of handling them.

This does not mean to belittle Android and improve iOS. It just shows that Apple has stronger control and self-control in the software ecology, so it should have a more mature frequency conversion strategy on the LTPO technology screen.

The new technology is like a piece of uncultivated black land, and the products of different manufacturers are like young trees that have just sprouted. In the process of growth, it always needs to be trimmed and pruned constantly to make it grow better and become a towering tree. The people who first arrived in this land to plant trees may not have enough experience and need to continue to explore the wall, while those who follow up can optimize according to their existing experience, so that their trees can grow faster.

To plant this new land full of saplings into a forest, more manufacturers need to participate, stimulate their wisdom, and continuously optimize the process of planting trees to make it more efficient and reasonable. The same is true for the LTPO technology screen. It may be a new feature of tomorrow's products. Its perfect presentation requires the participation of more manufacturers, whether it is the first batch of Samsung, OPPO, OnePlus, or later Apple, Xiaomi and so on.

On the new land of afforestation, they are worthy of our respect. With their development, we will have a whole forest to enjoy the shade and enjoy.

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