LTPO：Smart scene switching, smooth and power saving
Before talking about the HONOR Magic4，Let's briefly talk about what is LTPO。Back in 2018，The concept of LTPO has been proposed。 At that time, the refresh rate of mobile phones was generally 60Hz.，The effect of LTPO is not so obvious，It didn't attract much attention。
LTPO says it simply，That is, the refresh rate of the screen can be reduced to a minimum of 1Hz，and toggles back and forth between 1Hz and the highest refresh rate，While bringing high brush and smooth experience，To achieve the purpose of saving electricity from the source。
Since the mobile phone industry entered the era of high brushing，The refresh rate of mobile phone screens has been increased from 90Hz to 120Hz or even higher，Even some gaming phones support 144Hz，In addition, the resolution of top flagship screens like HONOR Magic4 is generally above 2K or even 2K，Power saving has become an urgent problem for manufacturers to solve，As a result, LTPO was once again taken seriously by manufacturers.。
For the mobile phone industry，The experience brought by high brushing can be said to be one of the biggest improvements in recent years，The smooth experience is far from what hardware improvements can match。 For many users，Low configuration can not play the game，But no high brush is obviously unacceptable。
But then again，when we use mobile，Not every moment needs a high refresh rate。
The highest frame rate of some games with more expensive configuration is only open to 60 frames，At this time, if the phone is still turned on at 120Hz or higher，Obviously a waste of electricity。
If it is reading software，Even 1Hz is enough，After all, the frame rate of a still picture is theoretically only 1 frame，High refresh rate is also a waste，At this time, LTPO is needed to help the phone adjust the refresh rate，to save electricity。
Different from the common LTPO on the market，Honor HONOR Magic4 supports multi-speed switching from 1Hz to 120Hz，Let's take a look at the actual effect。
In the settings we turn on the smart refresh rate，The screen refresh rate is 10Hz when the desktop is stationary，The screen refresh rate is 90Hz in the scrolling state。
The author has always believed that it is difficult for the human eye to perceive the difference between 90Hz and 120Hz，After all, the feeling of increasing from 90Hz to 120Hz is far less shocking than increasing from 60Hz to 90Hz，But since manufacturers are willing to use 120Hz，as an ordinary consumer，Naturally, I would like to see this situation。
News app performance is not uniform，When swiping the Weibo page，The refresh rate is 90Hz，The refresh rate drops to 10Hz when stationary，Sohu interface keeps 60Hz when scrolling，10Hz at rest。
The biggest difference between Weibo and Sohu App should be that there will be auto-playing small videos on the homepage，Although few users upload high refresh rate videos，But it is quite thoughtful to take precautions like Honor Magic4。
To test whether this idea is correct，The author opened the Ctrip App again，After all, with the popularity of short videos，Apps like Ctrip will also have promotional videos。
at rest，The refresh rate of Honor Magic 4 is 10Hz，60Hz screen refresh rate when not playing video，The refresh rate rises to 90Hz when playing video，Basically the same as the Weibo refresh rate adjustment logic。
Apps like QQ that pop up animation effects from time to time，In the chat interface, the refresh rate of Honor Magic 4 has been maintained at 120Hz，And to the QQ space interface，The refresh rate is automatically adjusted to 60Hz。
In general，The refresh rate of HONOR Magic4 basically switches between 10Hz and 120Hz，Did not encounter the refresh rate to 1Hz，Even when using eBooks，Also because of scrolling ads, the screen refresh rate reaches 10Hz，It may be that the current test prototype or system needs to be further optimized and adapted。certainly，10Hz is also very power efficient，Even reading e-books is enough。
The most pleasing thing is in daily use，Most of the high refresh rate scenes of Honor Magic4 only adjust the refresh rate to 90Hz，No blind boost to 120Hz，Enjoy the smooth pleasure of high brushing，It also saves battery power for your phone，This deserves a thumbs up。
Four、1920Hz high frequency PWM dimming：Top eye protection, long-term use of glasses is not sour
Before introducing the 1920Hz high frequency PWM dimming of the Honor Magic4，Let's briefly talk about what is PWM dimming。
The full name of PWM is Pulse Width Modulation，Pulse Width Modulation，The backlight of the screen is constant under PWM，For example, we adjust the screen brightness to 50%，with constant backlight，PWM controls brightness by periodically controlling how long the backlight is turned on and off，That is, 50% bright screen、50%screen，Since the adjustment process is completed in a very short time，and the persistence of vision effect of the human eye，In terms of visual effects, it becomes 50% brightness。
but，PWM has a burning problem，That's strobe，The lower the frequency, the more serious the flicker，This is also the direct reason why users feel uncomfortable with glasses when using low-frequency PWM mobile phones。
There has always been a saying，That is the best eye protection for Apple mobile phones。 Not to mention whether this statement is correct，In fact, the PWM dimming frequency of iPhone 12 is 240Hz，iPhone 13 all series PWM dimming frequency 480Hz。
Honor Magic series has reached 1920Hz PWM dimming frequency since Magic3，Honor Magic4 is also 1920Hz，But it seems that few people praise the glory of mobile phone eye protection。
word of mouth，Let's take a look at the actual experience results。
in comparison，I brought a contemporary iPhone 13 Pro，This phone has a PWM dimming frequency of 480Hz。 In comparison with Honor Magic4，Adjust the brightness of both phones to 50%，The shutter speed of the mobile phone is adjusted to 1/2000。
not difficult to see，The strobe of the Honor Magic4 remains in a very stable range，Only 1 low bandwidth streak in both comparisons，while the iPhone 13 Pro has 5，More ripple means lower flicker，more damage to the eyes。
look at it from a different angle，The difference between the two phones is even more obvious，Honor Magic 4's low bandwidth stripes disappear，while the iPhone 13 The Pro still has 4 low bandwidth stripes，Obviously, the Honor Magic 4 needs more eye protection。