Review of Xiaomi Mi Mix 4 - the main innovations in one bottle

26.08.2021 24158 2














Video review

appearance Mi Mix 4

On August 16, Xiaomi showed its long-awaited new product - the Mi Mix 4 smartphone with an under-screen camera. According to the manufacturer, it should be a real luxury with advanced technology. We do not expect anything else from Mi Mix 4, because the cost of the device, for a minute, is a thousand dollars. What can the Chinese offer for such a price and is Mi Mix 4 so good - we will find out in this review.

Main characteristics

Specifications Mi Mix 4

Consider how all the parameters of the novelty look on paper. At first glance, this is a beast with top-end features: the latest processor, maximum memory, powerful main camera, sub-screen front camera, fast 120-watt charging. Cool, right?

Display Diagonal 6.67″
Matrix type and resolution: AMOLED, Full HD+ (1080 x 2400)
Screen protector: Corning Gorilla Glass Victus
Body Material: Ceramics
Colours: Ceramic Black, Ceramic White, Shadow Gray
Dimensions: 162.6mm x 75.3mm x 8.0mm, weight 225g
Processor: 5nm Qualcomm Snapdragon 888+ 5G with 1 Kryo 680 core at 2.99GHz, 3 Kryo 680 cores at 2.42GHz, and 4 Kryo 680 cores at 1.80GHz
Graphics accelerator: Adreno 660
Network support 2G, 3G, 4G and 5G
Memory: 8/128 GB, 8/256 GB, 12/256 GB, 12/512 GB
Main camera 108 MP f/1.9 + 8 MP f/4.1 (periscope telephoto) + 13 MP f/2.2 123˚ (wide-angle), 5x optical zoom and OIS
Front camera Subscreen, 20 MP with a focal length of 27 mm
Communications: Wi-Fi 6, Bluetooth 5.2, Dual Band A-GPS, GLONASS, GALILEO, NFC, Infrared
Battery: 4500 mAh, fast wired charging at 120 W and fast wireless at 50 W, support for Quick Charge 4 and Power Delivery 3.0 technologies
Price: 8/128 GB $771, 8/256 GB $817, 12/256 GB $894, 12/512 GB $972


Mi Mix 4 equipment

We got acquainted with the main characteristics, and now we proceed to a thorough study of the smartphone. Mi Mix 4 comes in a black rectangular box with a golden "Mix" lettering in the center. The packaging really looks expensive and stylish. Opening it, we see the mobile device itself and, of course, additional gadgets, such as a heavy 120W power supply, Type-C cable, audio adapter and a silicone case. The latter is puzzling, since the quality of the cover is disgusting and does not exactly correspond to the declared premium level. The same Redmikov for 150-200 bucks has the same bad cover in the kit. Also where is the suite for Mi Mix 4?

film on screen Mi Mix 4

The film is already pasted on the screen, but this is a common occurrence in Xiaomi phones. By the way, the film emphasizes the cutout for the front camera. That is, we do not see the module itself, but there is a round cutout in the center.

Appearance and dimensions

Mi Mix 4 dimensions

You can't fault the design of the fourth Mi Mix. The phone really looks elegant and minimalist. There is no cutout for the front camera on the front panel, the speaker is also securely hidden. The block of the main camera is made neatly and strictly, for which a special like to the manufacturer. The only thing that slightly spoils the impression is the rather large black frames, although they are rounded. Especially black frames stand out in white and gray colors.

If the front panel is almost flawless, then there are already complaints about the back cover. The color schemes of the body look very simple and trite. The premium color is Shadow Gray , but in reality, the color can be described as a dirty light gray. For an amateur. The Ceramic Black and Ceramic White colors are just black and just white, no creativity. Yes, this is a classic, but we are already used to beautiful unobtrusive gradients, as, for example, in Mi 11 . Well, of course, it all depends on your preferences.

ceramic case Mi Mix 4

Mi Mix 4 is completely made of luxury material - ceramics. It feels nice in the hands and looks great, but practicality is out of the question. Ceramic cases break easily, so a case is a must. That's just where else to find a quality case, right?

face of Mi Mix 4 case

On the right side there is a power button and a volume rocker; on the bottom - a Type-C port, a multimedia speaker and a SIM card tray; on the top - the second multimedia speaker and microphone + infrared port. The left side is completely empty. There is no headphone jack, as well as a memory card tray. Thank you at least for including the Type-C to AUX adapter in the kit.

Mi Mix 4 case dimensions

In terms of dimensions: Mi Mix 4 has quite impressive dimensions, namely 162.6 mm x 75.3 mm x 8.0 mm with a weight of 225 grams. However, nothing surprising: these are standard dimensions for modern smartphones. Perhaps someday we will wait for a compact model, but hardly in 2021.

Display quality

Mi Mix 4 display quality

In Mi Mix 4, of course, an AMOLED matrix is installed. But the resolution is only Full HD + (1080x2400 pixels). Competitors in this price category almost always have a resolution of 1440 by 3200 pixels, and here such a disappointment. But this can be explained logically: if Mi Mix 4 had a higher resolution, then it would not be possible to hide the under-screen front camera. If you want an invisible front camera, you will have to put up with such a resolution (and not only with it, but more on that later).

Mi Mix 4 screen brightness

The screen itself is of good quality, the color reproduction is correct, the viewing angles are excellent. Brightness is sufficient even in sunny weather. According to the technical parameters, we have a maximum brightness of 800 nits here. By the way, this is less than the Mi 11 and Mi 11 Pro (1500 nits). It also supports HDR10+ and Dolby Vision. The screen refreshes at 120Hz and 60Hz. PWM protection is only available at a frequency of 60 Hz, and there is not much sense from it. Look, here are the flickering results of Mi Mix 4 with the DC Dimming function active :

  • 100% - 18%
  • 50% - 18%
  • 25% - 18%
  • 0% - 16%.

And here is the picture we get if the protection is disabled:

  • 100% - 18%
  • 50% - 18%
  • 25% - 32%
  • 0% - 11%.

Agree that the difference is insignificant.

Another stone thrown into the Xiaomi garden is related to the fact that the company still does not implement LTPO displays in its flagships. For the first time, the technology should appear in Mi 12 - or rather, Xiaomi 12. By the way, you can write in the comments how you like this whole rebranding story and whether you approve of it. Personally, I don't.

Performance, gaming and heat

Mi Mix 4 case heating

We are moving smoothly towards the processor. Xiaomi Mi Mix 4, as a true flagship, received a top-end Qualcomm Snapdragon 888 Plus 5G processor with an Adreno 660 video accelerator. The maximum clock frequency reaches as much as 2.99 GHz. Why do you need such a cool performance? That's right, for games. Will you be able to play comfortably - no, and here's why.

We all know that the latest processors from Qualcomm get terribly hot. The manufacturer promised to fix this problem, and at the presentation of Mi Mix 4 we were told with fervor that the smartphone has a liquid cooling system, thanks to which there will be no heat. As always, we tested the phones in two popular and very demanding games: Shadowgun Legends and Genshin Impact. The result is disgusting, let's just say.

Mi Mix 4 performance

The problem with heating was "resolved" as follows: the manufacturer simply cut the processor's power in games. Shadowgun Legends, running at ultra-high settings, averaged 37 frames for the first 15 minutes, sometimes there were subsidences up to 13 FPS. Of course, in this scenario, the phone did not warm up, but 37 FPS is the level of mid-budget smartphones based on the Snapdragon 720G chip. And after 15 minutes went the heat in the truest sense of the word. By some miracle, the power block turned off on its own, we got the maximum FPS and fierce heating up to 60 degrees. At this temperature, it’s not that comfortable to play, it’s even problematic to hold the device in your hands. Imagine the sensations experienced by the battery and the rest of the inside of the device.

performance in Genshin Impact

Read also: Xiaomi Mi Mix 4 has another exclusive feature

With Genshin Impact, the situation is no less sad. Due to power blocking, the frequency did not go beyond 30 frames. Even forcibly setting a higher FPS did not work. The question is why Mi Mix 4 needs such a sophisticated processor if there is no sense in it. For everyday tasks, the same Dragon 720G is more than enough, and in the flagships we expect the implementation of cool solutions for games.

Due to the frantic heat, it was not even possible to conduct a graphics throttling test. In short, the performance in Xiaomi games failed.

Memory Options

Mi Mix 4 memory options

In terms of memory modifications, the company has not been stingy. There are four options: 8/128 GB, 8/256 GB, 12/256 GB and 12/512 GB. The top version with 12 and 512 GB is very expensive, of course, but its implementation is still cool. Since SD card is not supported, don't skimp on internal storage.

Firmware and stability

Mi Mix 4 firmware

Another hyped feature of Mi Mix 4 is the latest MIUI 12.5 Enhanced Edition firmware. In terms of functionality, you will not find anything new here when compared with the usual Miyuay 12.5. But the optimization really pumped. For several days of use, Mi Mix 4 worked quite stably, without crashes, freezes and independent reboots. This is cool, considering what problems are observed with the software in other new Xiaomi products . The same state employee Redmi 10 lags wildly under the control of the standard MIUI 12.5.

In general, MIUI 12.5 Enhanced Edition is like a stable version of the regular MIUI 12.5 that was in beta. There is nothing "elevated" and extended in it.

Main and front camera

Mi Mix 4 main camera

The main camera of Mi Mix 4 is triple: 108 MP + 8 MP + 13 MP. And she really takes good pictures both in the daytime and at night. There is a problem with saturation. All pictures are too faded and somehow uninteresting in terms of color reproduction. In general, this situation is periodically observed in Xiaomi smartphones. Redmi Note 10 5G also produces boring photos devoid of brightness. This is especially noticeable against the background of competitive phones from Realme. The wide-angle 13-megapixel lens is decent, the viewing angles are wide, everything is as it should be. The 8 MP telephoto is no less cool, as it has a 5x optical zoom along with optical stabilization. These are truly flagship options.

Camera Mi Mix 4

Video writes at a maximum resolution of 8K@24fps. The sound recording is excellent. In short, the main camera of the Mi Mix 4 is quite good. But keep in mind that it still loses Mi 11 Pro and Mi 11 Ultra.

Mi Mix 4 front camera

Unfortunately, the above praise does not apply to the front camera, which turned out to be a failure. The front camera has a 20 MP module with a pixel size of 0.8µm and a focal length of 27 mm. Let's drop the numbers and immediately consider examples of selfies. The front camera takes pictures and shoots blurry even in good lighting. You can only record video in 1080p@30fps. No detail, clarity and good brightness. The sound is terrible. This low quality is caused by the fact that the module is under the surface of the screen. Even Xiaomi representatives admitted that the front camera turned out to be mediocre. This is the price we have to pay for a completely invisible module. That is why under-screen technology will not be used in all fresh flagships. In the era of social networks, many people need a great (albeit noticeable) front camera. That's the way it is, friends.

Communications and mobile networks

Mi Mix 4 communications

As you can see, we mostly criticize Mi Mix 4, but this smartphone still found something to surprise us with. At the presentation, much attention was paid to mobile networks. The phone received a lot of antennas, thanks to which it copes well with communication. It really is. Mi Mix 4 catches a Wi-Fi signal where other smartphones are already disconnected from the network. The novelty gives out 4G without problems even in places with poor coverage. Support for 5G, of course, is also implemented, but so far it is neither cold nor hot from it.

An interesting point: Mi Mix 4 supports all common European bands, including the 20th, 7th and 3rd. Although outside of China, the phone is unlikely to be sold. You can only order the Chinese version from some Chinese online store. But is it worth it....

Let's get back to communications technology. Everything is decent here: Wi-Fi 802.11 a / b / g / n / ac / ax, Bluetooth 5.2, a full set of navigation services, an infrared port and an NFC module, which, by the way, works in our countries.

vibration motor Mi Mix 4

The vibration motor is cool, flagship. But the proximity sensor is still junk. Xiaomi still can't figure it out. Agree that it is very unpleasant when a smartphone for $ 1000 has a lagging sensor.

Battery, fast charging and battery life

quick charge Mi Mix 4

In terms of autonomy, everything is more or less normal. Xiaomi Mi Mix 4 received a 4500 mAh battery with support for 120 W wired fast charging, capable of feeding the battery up to 100% in just 15 minutes. Impressive, right? But such lightning-fast charging is not at all in favor of the battery. Be prepared for the battery to wear out in a year or two. During fast charging, the maximum heating was 54 degrees. That's quite a lot. It's good at least that the settings provide an option to adjust the charging power.

Wireless charging is also available, it is 50 watts. The thing is convenient, but you have to buy additional gadgets to use it. In our signature battery test , the Mi Mix 4 only lasted 8 hours and 15 minutes. Average, could be much better.

Speakers and sound

speaker Mi Mix 4

This is what Mi Mix 4 truly boasts of - awesome sound. The phone has stereo speakers from Harman/Kardon. The sound is true at the flagship level: loud, powerful, juicy. Not every expensive phone can offer such a chic sound.


Mi Mix 4 is expensive even in China:

  • 8/128 GB - $771;
  • 8/256 GB - $817;
  • 12/256 GB - $894;
  • 12/512 GB - $972.

If the novelty is still sold in Europe, the price will rise by another 300-400 dollars. It's so bad.


Conclusions Mi Mix 4

Well, it's time to sum up, and they are disappointing for Mi Mix 4. Do we recommend purchasing this new product - NO. For such money, you can find an excellent flagship, albeit with a noticeable front camera. Mi Mix 4 is absolutely not optimized in terms of processor heating (power blocking is not optimization at all, but complete stupidity), the front camera photographs frankly badly, the proximity sensor is buggy, the screen resolution is also not flagship. Hidden front camera is not worth all these sacrifices.

See what happens: a top-end processor is declared on paper, but in reality it is impossible to play because of the crazy heat; the manufacturer praises the hidden front camera, and it is quite unpleasant to use it due to the poor quality of photos and videos; we are waiting for interesting color solutions, but we get boring colors and a terrible case to boot; the hyped 120-watt charger will not only instantly charge the battery, but also quickly render it unusable. This is exactly the case when expectations were not justified from the word at all.

It is better to wait until really good smartphones with an under-screen camera appear on the market, but for now, take a closer look at the Mi 11, Mi 11 Pro or Mi 11 Ultra if you want to feel the premium of a mobile device.

Xiaomi Mi Mix 4 back cover


  • Cool stereo sound and vibration motor.
  • As such, the lack of a front camera on the front panel.
  • Royal modifications of memory.
  • Excellent networking support.
  • Good main camera.
  • Stable firmware.


  • Excessive processor heat.
  • Automatic power lock in games.
  • Mediocre screen resolution (for the flagship level).
  • Fast discharge.
  • It is not known whether there is moisture protection and to what extent.
  • Significant problems with the proximity sensor.
  • Unjustified cost.

Also, don't forget to watch our video review and write your opinion about Mi Mix 4 in the comments (please, no harsh statements). Good luck to all!

Video review

Author: Алина Никитина Publication date: 26.08.2021


Total comments: 2
negru vadim 0
По корпусу очень похож на Redmi K20\Mi 9T. Рамки даже у микса на вид чуть больше, добавили ик, убрали джек.
06.12.2021 11:35
Иванов Сергей -3
Угу, предложи своей бабе: -Тебе дорогая что купить, Сяоми или Айфон?
24.09.2021 17:13


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Review of Xiaomi Mi Mix 4 - the main innovations in one bottle