Xiaomi MI 9 SE Specifications, Tests and Review

The Xiaomi MI 9 SE has a height of 147.5 mm, a width of 70.5 mm and a thickness of 7.45 mm. The weight of the phone is 155 g.

The screen size reaches 5.97" inches. With a large display, phone offers a great experience for watching videos, playing games and reading. The best phones today are 6.5'' or more. They have the advantage of a large display area that allows you to see more content than with conventional display sizes. Owing to OLED technology, the display offers a true representation of colours, especially black. The resulting contrast is significantly higher and colours appear more vivid. OLED technology is now part of most smartphones, while LCD displays are becoming a thing of the past in mobile phones. OLED displays also have lower power consumption compared to LCD technology.

Display Resolution of Xiaomi MI 9 SE is 2340 x 1080 pixels. A higher display resolution is a prerequisite for a sharper image. The standard for mid-range phones today is a Full HD resolution of 1920 × 1080 px. Cheaper phones, which usually have a smaller diagonal, have an HD resolution of 1280 × 720 px. Smaller resolutions can only be found in older models. Best phones, on the other hand, have a 4K resolution of 3840 x 2160 px. Display´s pixel density is 432 ppi and represents another significant factor affecting image sharpness besides resolution. The higher the value, the sharper the image. Average value is currently about 350-400 ppi, which guarantees a fine and sufficiently sharp image. Finest modern phone displays reach 450 ppi and above.

Xiaomi MI 9 SE is equipped with Qualcomm Snapdragon 712. The number of processor cores is 8. It is a number of cores that plays an important role in evaluating the performance of phone as it is responsible for computing operations. Smartphones already commonly have a core count of around 4 to 8. Multi-core processors can perform better and reduce the processing time of a request to a minimum, which is reflected in the responsiveness of the phone, e.g. in the speed of opening applications. The processor frequency indicates how many instructions phone can process in 1 second. The higher the frequency, the better the performance. Standard processor frequency range today is between 1.8 GHz and 2.8 GHz. Xiaomi MI 9 SE reaches the frequency of 2.3 GHz.

The processor also includes the graphics accelerator Qualcomm ADRENO 616.

The phone´s internal memory capacity is 64 GB. The size of the internal storage determines e.g., how many photos, songs, movies, or applications you can store on your phone. For everyday use and storing photos, songs or movies, this medium-sized internal storage is ideal. The advantage is also a lower price of phones equipped with this storage capacity. Best phones today range from 256 GB to 1 TB. That size is suitable for the most demanding users who shoot a lot of high-resolution photos or videos in 4K. Nevertheless, you'll have to pay extra for these higher capacities. Luckily, most smartphone manufacturers nowadays offer models with different memory sizes to suit every user.

RAM memory of the Xiaomi MI 9 SE is LPDDR4X SDRAM - 6 GB. Most powerful phones currently have an operating memory of 12 GB or more, which is especially useful for demanding users such as gaming enthusiasts. Normally, phones nowadays have 6 to 8 GB of RAM, which means that the phone can easily handle normal operation and more demanding applications. Operating memory of less than 4 GB is found in lower-end phones or older models, and they are suitable for low-end users who don't use demanding applications and have the phone more for basic use.

The rear camera of the Xiaomi MI 9 SE is equipped with 3 lenses, with each lens having a different role in taking pictures. Most common lens you'll see on smartphones is a wide-angle lens, telephoto lens or macro lens. A wide-angle lens is mainly used to capture landscapes and other spatially larger compositions where a wide field of view is needed. A telephoto lens is designed for photographing subjects at a distance and often has an optical zoom. A macro lens is ideal for close-ups and small objects. The main lens is designed as Wide-angle lens. The resolution of the main lens is 48 Megapixel. Higher resolution does not necessarily mean super high quality photos. Furthermore, it depends on the pixel size but also on other important factors. The aperture of main lens reaches F/1.75 value. The best phones have a lens with an aperture of up to F/1.5, where more light can pass through sensor and photos will be of a high quality even in low light conditions. However, lenses with apertures around F/1.8 to F/2.2 are the most common. The lower the number after the slash, the better the photo quality.

Digital zoom in this case offers zooming up to 10x. Of course, the higher the lens value, the more distant object can be zoomed in. Nonetheless, the disadvantage of digital zoom is that the quality and sharpness of photo deteriorates when using it. Much more important is the optical zoom, which has the advantage of not losing quality and sharpness when zooming in. On this phone, the optical zoom is 2x. Some users will also appreciate facial recognition feature, which allows camera to recognise the face of person in frame and automatically focus on it.

Second camera
The second lens of rear camera is designed as Ultra wide-angle lens. The field of view of second lens reaches 123 degree(s). The resolution reaches size of 13 Megapixel. Furthermore, the second lens is equipped with aperture of F/2.4.

Third camera
Lens number three represents the Telephoto lens. The resolution of third lens is then 8 Megapixel. The pixel size that significantly affects quality of photo is 1 μm. Last but not least, third lens is equipped with a lens aperture of F/2.4.

Front camera
The front camera of phone Xiaomi MI 9 SE has one lens. This number of lenses is standard on most smartphones nowadays. The resolution of front lens reaches 20 Megapixel. Again, it should be noted that resolution is only one of several other significant factors that affect resulting quality of a photo.

The facial recognition feature is just a nice cherry on top.

The battery size of Xiaomi MI 9 SE is 3070 mAh. Nevertheless, battery capacity is not the only factor that affects the phone's battery life. For example - the size of the display, the performance of the processor, the use of data functions and, of course, the intensity of use of phone in general all have a significant impact on battery life. Standard for most smartphones today is a battery capacity of around 4500 to 5000 mAH. Phones with this battery size usually guarantee a phone life of at least 1 day. Older or cheaper smartphone models can then reach battery capacities typically around 2500 mAH and below. With this capacity, you may find that if you use your phone heavily, you may need to recharge your phone during the day. The fast charging function will also please many people. Owing to fast charging, phone charges up to several times faster, which you will appreciate, for example, on the go.

Xiaomi MI 9 SE supports 4G. 5G connectivity, which is slowly replacing standard 4G connectivity, is still more the preserve of the latest phones. This model also offers ability to pay by phone with Google Pay.

Fans of modern technology will appreciate NFC function, which allows, among other things, contactless mobile phone payments, but also finds other uses in connectivity, such as unlocking the door or loading the menu in restaurant using the NFC tag. Basic connectivity standards also include Bluetooth 5.0, making it easy to communicate wirelessly with other devices such as headphones, tablets, speakers and smartwatches.