To say the most representative mobile phone of 2000 yuan in 2021，The Redmi K40 series that has been guarding the gate for a whole year，must be nominated。Excellent Samsung E4 AMOLED flagship straight screen，Snapdragon 870 + LPDDR5 memory + UFS 3.1 flash memory performance three-piece set，Such a quasi-flagship configuration，such price，Even today it can still be called”real incense machine”，See how capable。
With the recent release of the Redmi K50 series，The K40 series also blooms on old trees，Brought us a refreshing Redmi K40S ，Conscience upgrade from four aspects，And the price is even lower，Can be described as”Increase the quantity and reduce the price”。Now for the bright black colorway、12GB+256GB version of Redmi K40S 。
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Redmi K40S Unboxing Tour
Since as a "flagship welder"，Extreme stacking is also a tradition of Redmi，This Redmi K40S inherits the classics at the same time，Also brings a new design。
Samsung E4 material flagship AMOLED straight screen、Snapdragon 870 + LPDDR5 memory + UFS 3.1 flash memory”Performance Audio-Technica”、4500The mAh battery is fully preserved。
Upgrading，First, it brings the same design and color matching as the Redmi K50，Adopt the most popular straight edge frame design，The body is also thinner。
Post-photographic primitives remain unchanged，But added the OIS optical image stabilization that was missing from the K40，Even many high-end machines with three or four thousand CNY may not have，It is guaranteed to have a very high rate of shooting at random。At the same time, the liquid-cooled copper tube becomes 3112 square mm VC liquid-cooled heat dissipation，Area increased by 400%，Can bring better cooling effect。The fast charge has also been upgraded from 33W to 67W，Further reduction of charging time。
Now，Let's take a look at the performance of this K40 upgrade - Redmi K40S，The following figure shows the specific parameters：
Exterior：The straight-edge middle frame is very tough, and the rear camera shape is the same as the K50 division.
The front of the Redmi K40S uses a 6.67-inch Samsung E4 luminous AMOLED flagship straight screen，Resolution is 2400×1800，Support 120Hz refresh rate、360Hz touch sampling rate，Contrast is 5 million：1，Support HDR+、MEMC frame rate compensation，Peak brightness up to 1300nit，Global brightness up to 900nit。
The screen is made of Corning Gorilla Glass 5, which is resistant to wear and tear.，The screen opening is 2.76mm，20 million front camera stuffed，Support AI beauty and other features。
The back design of the Redmi K40S is the same as the K50 series，overall very simple，With the distinctive square and round collision design，Different from the language design of Redmi K40。
The Redmi K40S rear camera consists of a 48-megapixel main camera lens + 8-megapixel ultra-wide-angle lens + 2-megapixel macro lens，The entire module is in the shape of a two-stage ladder，The lower part is the fill light and 48MP OIS logo。
One of the upgrade highlights of the Redmi K40S is the use of a rounded appearance instead of a trendy small standing edge design，It looks a lot tougher，But the edges are rounded and over-processed，It doesn't look awkward when you hold it in your hand。The physical button is on the right side of the fuselage，Up is the volume plus and minus keys，Below is the power button that supports fingerprint recognition。
Top and bottom local details，In addition to the regular USB-C interface and SIM card slot，Redmi K50 also supports dual speakers and infrared。The Redmi K40S comes with a 67W charger in the box。
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Redmi K40S performance test：The quasi-flagship-level performance of the Snapdragon 870
Redmi K40S is powered by Qualcomm Snapdragon 870，This processor is the game god U，Balanced power consumption and performance，One of the most popular chips on the market，Even a lot of tablets are using it。
This wafer specification is based on a 7nm process，The CPU consists of 1 3.2GHz super core + 3 2.42GHz large cores + 4 1.8GHz small cores，At the same time, it forms a three-piece performance set with LPDDR5 memory + UFS3.1 flash memory。
——AnTuTu
AnTuTu scored 723322 points，The performance of the conventional Snapdragon 870，more than 66% of users。The CPU score is 194831 points、The GPU score is 241428 points、The memory score is 130842 points、UX score is 156221 points。
--Master Lu
Master Lu ran out of 844046 points，But more than 99% of the mobile phones are a bit exaggerated。The CPU score is 284593 points，The GPU score is 323309 points，Memory score is 102540 points，Storage score is 133604 points。
——GeekBench
We chose GeekBench 5, the mainstream processor benchmark software on the market, for testing.，The grade given is a single core 1029，Multicore 3384。
——GFXBench
GFXBench's performance，In terms of results，The GPU that belongs to the Snapdragon 870 should have the results，quite satisfactory。
——AndroBench
in Androbench，Measured sequential read speed of 1578MB/s，Belonging to the performance of UFS 3.1 flash memory
From the above results， The performance of Redmi K40S and K40 is not much different，In the case of mature performance tuning of Snapdragon 870，There is not much room for further digging。
certainly，Snapdragon 870's mature power consumption adjustment level and stable flagship performance release capability，It also makes this crystal enduring，still on the market”most fragrant”wafer。
Redmi K40S gaming test：120Hz screen blessing, the game experience is silky and smooth
- Ace Warrior
In "Ace Warrior"，We changed the picture quality and frame rate of the game to the highest，Allow automatic lowering of quality and frame rate off。
during quick battles，The frame rate is basically maintained at 120 frames，very stable，Remove frame rate fluctuations caused by death，The average frame rate is 115 frames。
——QQ Speed
In "QQ Speed"，We changed the game's graphics settings to ultra high，Intra-office frame rate、Outside frame rate changed to very high，Resolution changed to ultra clear，The effect level is high。
in a quick match multiplayer match，The overall frame rate is above 122 frames，Although fluctuating，But the average frame rate is also 120 frames。
——Genshin
Want to understand the performance release and tuning capabilities of mobile phones，It is most suitable to test with "Original God"。We changed the game image quality to very high quality，Frame rate changed to 60fps。
During the game of Genshin Impact，We randomly fight monsters in multiple scenes、Run for 15 minutes。After entering the game，The initial frame rate is 55 frames，But as the game gradually heats up，The frame rate also gradually drops further，The second half is basically stable at 48 frames。Simultaneously，We detect with infrared thermal imager，The temperature of the SoC area of the mobile phone has reached around 42°C。
The above mainstream games，The performance of the Redmi K40S can run smoothly，But from the experience of "Original God"，Game scheduling is slightly conservative，This should be a trade-off between heat and performance for Redmi K40S，It is recommended that players lower the picture quality appropriately，for the best gaming experience。
Redmi K40S camera effecttest：IMX582 with OIS optical image stabilization can take pictures at will
The rear camera of Redmi K40S is a solution composed of 48 million main camera lens + 8 million 119° ultra-wide-angle lens + 2 million macro lens。The main camera is Sony IMX582，1/2″ photosensitive element，f/1.79 large aperture，The K40 lacks OIS optical image stabilization，It is also completed on K40S。Let's take a look at the camera effect of Redmi K40S：
In the case of sufficient light，The IMX582 main camera lens with OIS optical image stabilization has obvious advantages，The screen is transparent and bright，It is also more pleasing in color performance。
After adding optical image stabilization，Can effectively reduce image blur，Improve film yield，No more fear of shaking hands when taking pictures”paste”Lost。but，Obvious chromatic aberration and white balance inconsistencies in the ultra-wide-angle lens，It is recommended to use the main camera。
Night scene proofs：
Although there are only 2 million macro pixels，but shooting flowers、The advantage is very obvious when such small natural scenery as green plants，Especially the white flower part on the top，texture、pistil，can be clearly expressed。
in night view，Redmi K40 is great for both neon lights and architectural lights，Everything is under control，At the same time, it can also restore the object details and color atmosphere，Even in the face of complex text lighting effects, it can be suppressed steadily，basically no glare。
certainly，It is recommended to avoid strong light and complex lighting environment when taking pictures，Otherwise, there may be ghosting in the proofs、Halo etc.。
battery life and charging：67W fast charging only takes 40 minutes to fully charge
——Charging test
Redmi K40S is also upgraded from 33W to 67W fast charging，Built-in 4500mAh single-cell battery。We start charging from 5%，20Charge to 47% in minutes，80%Then enter the protection charging mode，Significantly slowed down，Takes 40 minutes to fully charge。
- battery life test
For battery life，We use the professional battery life test tool battery dog for testing。on the test project，We choose the extreme battery life test，Checked include CPU high voltage、CPU multithreading、AI recognition、Picture Viewer、video playback、All test projects for web browsing，Analogy to real-life usage scenarios，Restore the real load to the greatest extent，Infinitely close to the real power consumption。
We set manual 50% brightness，From full blood to shutdown，Total time spent 8 hours 02 minutes，It is in line with the expected results of the Snapdragon 870 model equipped with a 4500mAh battery. According to the usage habits of ordinary users，It can be used intermittently for a day without any problem。
overall，Redmi K40S can be said to be the combination of K40 and K50”mixed race”，still maintained a high”goalkeeper”Quasi-flagship machine level。
Appearance，Naturally consistent with the design language of the Redmi K50 but different，Also differentiated from the Redmi K40，Different shapes also bring freshness to consumers。
Although it adopts a straight edge shape，Redmi K40S has also optimized the hand feel，The edge of the fuselage has been rounded and excessively processed，It won't hurt when you hold it in your hand，still very comfortable。Even more rare is，In the case of changing the shape，Redmi K40S body thickness is only 7.7mm，Weighs only 195g，Even slightly thinner than the K40、slightly lighter。
Needless to say, the quasi-flagship performance of Snapdragon 870+LPDDR5 memory+UFS 3.1 flash memory，Although epistar tuning is slightly conservative，However, the performance and power consumption of the Snapdragon 870 have been witnessed。
As the most popular wafer in the market，Plus 3112 square mm VC liquid cooling，Let users even play games with high load such as "Yuan Shen"，The highest temperature in the wafer area is only 42 degrees Celsius，Keep the fuselage within a reasonable range，Let players play games longer。
Redmi K40S is also one of the few models that uses high-quality AMOLED flagship direct screen，120Hz high refresh rate that can enhance the gaming experience、360Hz touch sampling rate is not absent，Also supports Dolby Vision and HDR10+ high dynamic range display，With Dolby Atmos dual speakers。In games or video experience，This Redmi K40S can bring users excellent visual enjoyment。
OIS optical image stabilization is a surprise among surprises，Not to mention the same grade of mobile phones in the market，Even fancier products are rare，Practical experience day or night，No matter the distance or macro，Don't worry about shaking hands anymore。
There is also an upgraded 67W fast charge，Charges 4500mAh battery to 50% in 10 minutes，40Full blood in minutes，Can also provide 8 hours of use under high load。
It can be said，Redmi K40S on the screen、performance、Photograph、There are no shortcomings in all aspects such as fast charging，Even cheaper after the upgrade。
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