Overview of the Cubot X90 smartphone

Cubot is a second-tier Chinese smartphone manufacturer that mainly offers budget models, but from time to time tries to stand out from the competition. The new Cubot X90 model really catches the eye: it has a curved waterfall screen and a 100 MP camera. The device is not too expensive, but it looks quite interesting. Let's check out its capabilities!

• SoC Mediatek Helio G99, 8 processor cores (2×Cortex-A76 @2.2 GHz + 6×Cortex-A55 @2.0 GHz)
• GPU Mali-G57 MC2
• OS Android 14
• Touchscreen AMOLED, 6.67″, 1080×2400, 20:9, 395 ppi, 120 Hz
• RAM 16 GB, internal memory 256 GB
• No microSD support
• Nano-SIM support (2 pcs.)
• Networks 2G GSM, 3G WCDMA, 4G LTE
• GPS, GLONASS, BDS, Galileo
• Wi-Fi 5 (2.4 and 5 GHz)
• Bluetooth 5.2
• NFC
• USB 2.0 Type-C, USB OTG
• 3.5 mm no audio output for headphones
• Cameras 100 MP + 16 MP (wide-angle) + 5 MP (macro), video 1440p@30 fps
• Front camera 32 MP
• Proximity and light sensors, magnetic field, accelerometer, gyroscope
• Fingerprint scanner (under glass)
• Battery 5100 mAh, charging 33 W
• Dimensions 162×74×9.4 mm
• Weight 207 g

Cubot X90 comes in a standard cardboard box with a nice, laconic design.

The accessory kit includes a connecting cable, a network charger (33 W) with a USB Type-C connector, a protective case and a protective glass for the screen.

The smartphone has a distinctive design reminiscent of the flagships of the past: strongly curved edges of both the front and back panels almost meet at the sides. There is no flat surface on the sides, only curves, which make it difficult to hold firmly in the hand. The device slides like soap. In addition, the curved edges of the screen cause glare, color distortion and accidental presses.

This design is hardly practical, but it looks really nice and impressive — especially if you haven't held such devices in your hands before. The smartphone seems more expensive than its price, but the creators clearly do not care about the practical side of the issue. For example, it will be difficult to find a protective coating for the curved screen, especially for a model that is not yet known on the market. However, the manufacturer included one protective glass for initial use.

The smartphone is quite standard in size and weight, as large and heavy as most modern models. However, the weight of 207 grams exceeds generally accepted standards. The reason for such weight is not entirely clear, because its battery is practically ordinary — 5100 mAh.

The weight is probably added by the massive overlay on the back around the cameras, and here it becomes a pity that the developers have stopped caring about reducing the weight of their mobile devices. Why do we need such a heavy and large part that seems metallic? What function does it perform to justify the increase in the weight of the smartphone?

As for the materials, they are a pleasant surprise. Unlike many «sub-flagships» and even «flagships» (for example, Realme GT 6) with plastic frames, the Cubot X90 has a metal side frame. It fits comfortably in the hand and feels cold — real metal cannot be confused with plastic. This gives the inexpensive Cubot X90 additional points in terms of quality.

The back cover is decorated with an additional pattern in the form of veins of real stone, like marble. It looks fresh, and in general the smartphone looks very good from the side.

Unfortunately, the side buttons are located on two opposite edges. When gripping the device, this can lead to involuntary pressing of the keys. It would be better if they were on one side — it would be more convenient. The buttons themselves are not very large, but they are elastic and provide a clear press.

The fingerprint scanner is built under the screen glass, which is inconvenient when using it with one hand — it would definitely be better to have it on the side power button. The optical sensor works well overall, but it is not as fast as the capacitive one, and does not respond to wet fingers. At the top of the screen, in the center, there is a single selfie camera.

The tray on the bottom edge can accommodate two Nano-SIM cards, one on each side of the sled. Memory cards are not supported.

In addition, a speaker, microphone and USB Type-C connector are installed on the bottom end.

On the top end there is an additional microphone hole and two strange stripes — perhaps this is just a decoration or an attempt to mislead an inattentive buyer. In any case, these are not slots, and there is no second speaker there. The smartphone also does not have an IR port. It is also worth noting that there is no 3.5 mm audio output for wired headphones.

The included case is not flexible. It is transparent and hard, covering only part of the side surfaces.

The case comes in two colors: bluish-greenish and black with a light pattern. The smartphone does not have full certified protection against dust and moisture.

The Cubot X90 smartphone is equipped with a 6.67-inch AMOLED display with a resolution of 1080×2400, protected by glass with curved edges. The physical dimensions of the screen are 70×155 mm, and the pixel density is 395 ppi. The screen frame is narrow: 2 mm on the sides and 3 mm at the top and bottom. A refresh rate of 120 Hz is supported.

The front surface of the Cubot X90 screen is made of glass with a mirror-smooth surface that is resistant to scratches. Judging by the reflection, the anti-glare properties of the screen are better than those of the Google Nexus 7 (2013). The outer surface has an effective oleophobic (grease-repellent) coating, which makes it easier to remove fingerprints and slows down their appearance compared to ordinary glass.

With manual brightness adjustment, the maximum value was about 315 cd / m², which is not very high. Even with excellent anti-glare properties, readability in the sun will be unsatisfactory. The minimum brightness with manual adjustment is 3 cd / m², which allows you to comfortably use the device in complete darkness. There is automatic brightness adjustment using a light sensor, located on the upper end (which raises some questions). In automatic mode, the screen brightness changes depending on the external conditions: in complete darkness it decreases to 5 cd/m², in office lighting (about 550 lux) it is set to 90 cd/m², and in bright sunlight it reaches a maximum of 315 cd/m². Although we were not completely satisfied with this result, we slightly increased the brightness in the dark, obtaining values ​​of 15, 90 and 315 cd/m² in different conditions. Thus, the automatic brightness adjustment function works adequately and allows the user to adjust the screen to their needs.

At high and medium brightness levels, significant modulation is observed with a frequency of 120 Hz. Below are graphs of the dependence of brightness (vertical axis) on time (horizontal axis) for different brightness settings.

At high and medium brightness, the modulation frequency is 120 Hz, but the modulation duty cycle is low, and the modulation phase varies across the screen area, making flickering invisible. With a significant decrease in brightness, the modulation switches to a higher frequency — 1920 Hz, and flickering also does not appear.

A mode with an increased refresh rate of up to 120 Hz is available in the screen settings.

In 120Hz mode, the smoothness of scrolling is significantly improved (while at 60Hz, scrolling looks too jerky, as if it corresponds to a frequency of no more than 30Hz). The modulation character remains unchanged.

This screen uses an AMOLED matrix — an active matrix on organic light-emitting diodes. A full-color image is formed using subpixels of three colors: red ®, green (G) and blue (B), with red and blue subpixels twice as small, which can be designated as RGBG. This is confirmed by a fragment of a microphotograph.

In the given fragment, you can count 4 green subpixels, 2 red (including 4 halves) and 2 blue (1 whole and 4 quarters), which allows you to fill the entire screen without gaps and overlaps. For such matrices, Samsung uses the PenTile RGBG designation. The manufacturer determines the screen resolution by the green subpixels, while it will be lower for the other two. This can lead to some unevenness of contrast borders and other artifacts, but due to the high resolution, they have little effect on the image quality.

The screen has excellent viewing angles. The brightness at an angle for both screens decreases noticeably (compared to the Nexus 7), but this smartphone has a much less pronounced drop in brightness. Therefore, even with the same formal brightness, the screen looks significantly brighter (compared to LCD screens), since it is often viewed at a slight angle. However, with a large deviation, white takes on a weak blue-green tint, while black remains truly black at any angle. It is so black that the contrast parameter is not applicable here. For comparison, photos are provided in which the same images are displayed on the screens of the smartphone and the second participant in the comparison at a brightness of about 200 cd/m², and the color balance on the camera is set to 6500 K.

A white field is displayed perpendicular to the screens:

Note the good uniformity of brightness and color tone of the white field (except for the clearly visible darkening and change in hue towards the curved edges).

And the test picture:

The colors on the smartphone screen look oversaturated (pay attention to the tomatoes, bananas, napkin and face color), and the color balance is noticeably different. We remind you that the photo cannot serve as a reliable indicator of the quality of color rendering and is provided for illustration purposes only. For example, the pronounced reddish tint of the white and gray fields in the photo of the smartphone screen is visually absent when viewed perpendicularly, which is confirmed by hardware tests using a spectrophotometer. This is due to the fact that the spectral sensitivity of the camera matrix does not match the characteristics of human vision.

It is worth noting that the image occupies the entire height of the screen (in landscape orientation) and goes onto the curved edges, which leads to slight darkening and color distortion. In bright light, these areas almost always glare, which makes it difficult to view images on the entire screen. Even films with an aspect ratio of 16:9 go beyond the borders, which interferes with viewing.

Several profiles and even the MiraVision settings system are available in the screen settings.

However, any attempts to change the brightness or color balance through these settings either do not lead to a result or cause serious color distortions. The only thing that helps is the «Restore settings» item.

Switching the state of the matrix elements occurs almost instantly, but when turned on, a step of about 8 ms wide can be observed (which corresponds to a screen refresh rate of about 120 Hz). For example, this is what the dependence of brightness on time looks like when switching from black to white:

In some conditions, the presence of such a step can lead to the appearance of trails that follow moving objects.

The gamma curve constructed using 32 points with equal intervals did not reveal any dips in either shadows or highlights. The exponent of the approximating power function is 2.25, which is slightly higher than the standard value of 2.2, as a result of which the image looks slightly darkened. At the same time, the real gamma curve deviates only slightly from the power dependence:

Let us recall that in the case of OLED screens, the brightness of individual image fragments changes dynamically depending on the content — it decreases slightly for light images. As a result, the obtained dependence of brightness on hue (gamma curve) may not fully correspond to the gamma curve of a static image, since the measurements were taken with sequential output of gray shades almost on the entire screen.

The color gamut is much wider than sRGB, and is close to the DCI-P3 space:

The component spectra (i.e. the spectra of pure red, green and blue colors) are very well separated:

The grayscale balance can be considered average, since the color temperature exceeds the standard 6500 K. The deviation from the blackbody spectrum (ΔE) increases significantly as the lightness of the shade decreases, which negatively affects the visual assessment of the color balance.

(The darkest areas of the gray scale can usually be ignored, since the color balance in them is not very important, and the measurement error of color characteristics at low brightness is significant.)

Of course, there is a setting that allows you to reduce the intensity of the blue component. Bright light can disrupt the daily (circadian) rhythm, but this can be solved by simply reducing the brightness to a low but comfortable level. Reducing the contribution of blue to correct the color balance does not make sense.

This smartphone probably does not support DisplayPort Alt Mode for USB Type-C, which means that there is no way to output image and sound to external devices via USB.

To sum it up, the screen demonstrates low maximum brightness (up to 315 cd/m²), and although it has good anti-glare properties, it is quite difficult to use it outdoors in sunny weather. In complete darkness, the brightness can be reduced to a comfortable level (up to 3 cd/m²). Automatic brightness adjustment also works adequately. The positive aspects of the screen include an effective oleophobic coating and a mode with a refresh rate of up to 120 Hz. Let's also recall the advantages of OLED screens: true black color (without reflections), good uniformity of the white field and a smaller drop in brightness when viewed at an angle compared to LCD screens.

Among the disadvantages, there is an excessively wide color gamut, which often leads to distortions and unnatural colors when viewing videos and photos, as well as an average color balance. In general, the quality of the screen leaves much to be desired. It's also worth noting that the curved edges of the screen only make things worse by creating color tone distortions, reducing brightness at the edges, and causing glare in ambient light conditions.

The Cubot X90 smartphone is equipped with three rear camera modules and one front camera:

• 100 MP, 1/1.8″, f/1.9, PDAF (main)
• 16 MP, f/2.2, 117˚ (wide-angle)
• 5 MP (macro)
• 32 MP, f/2.5 (front)

The main camera shoots 25MP photos by default with 4-in-1 pixel binning, but you can switch to full 100MP resolution.

There is no need to comment on the photo quality; it can be safely called terrible even in 25 MP mode, and it is not worth talking about 100 MP. The dynamic range is extremely narrow, there are overexposures everywhere, the sky is whitened, and the whole picture looks whitish. Detail in the center of the frame is more or less acceptable, but there are large areas of blurriness at the edges. Colors look dull. The camera is one of the weakest points of the smartphone, despite the loud marketing statement about «100 MP».

Here are examples of photos taken with the main camera in auto mode:

The second camera offers the ability to shoot at an even wider angle, but we can’t demonstrate its shots, as we simply didn’t notice its presence during testing (note: there is only one 1× button on the main viewfinder screen, there are no standard buttons for switching to another focal length). However, looking at the main camera’s shots, it’s hard to imagine that the ultra-wide-angle module (traditionally much weaker) will be able to create something outstanding.

The selfie camera shows about the same basic level of quality.

The maximum video resolution is 2.5K (1440p) at 30 fps, and 60 fps is impossible to achieve even when the resolution is reduced to 1080p. Video quality remains basic: the dynamic range is weak, details are blurry, the contour sharpness is too noticeable, and most importantly, strong flickering spoils the picture. The sound is recorded muffled.

The smartphone supports most mobile networks up to 4G, two Wi-Fi 5 and Bluetooth 5.2 bands, as well as NFC. However, it does not support 5G and e-SIM. Within Moscow, the device demonstrates stable operation in wireless networks, without losing connection and quickly restoring it after breaks. All the necessary built-in sensors, including a gyroscope, are present.

The single-channel satellite navigation module supports GPS, GLONASS, BDS and Galileo. Satellites are not detected very quickly during a cold start, but the positioning accuracy is at a good level.

The speaker provides high volume, and the voice of the interlocutor sounds clear and intelligible. The vibration call is noticeable.

The Cubot X90 smartphone runs on Android 14, which is an almost pure version of the OS, although with the presence of the DuraSpeed ​​function, which limits background processes. The device does not have pop-up ads and redundant pre-installed applications, and the interface works quickly. Full support for Google services is also present.

There are no stereo speakers in the smartphone, there is only one loudspeaker. However, the sound it produces is surprising: it is very loud, powerful and rich, which distinguishes the device from similar models in its price category.

The Cubot X90 smartphone is equipped with an eight-core SoC Mediatek Helio G99, and the graphics tasks are performed by the Mali-G57 MC2 GPU. The amount of RAM is 16 GB, the built-in storage is 256 GB (UFS 2.1). It is not possible to install a memory card, but it supports connecting external devices via USB Type-C in USB OTG mode.

Mediatek Helio G99 is a budget platform introduced on May 23, 2022 and manufactured using a 6-nanometer process technology. It demonstrates low performance, scoring less than 400 thousand points in AnTuTu, which corresponds to the entry level by modern standards. However, the interface works quickly, applications open without significant delays, and the performance is sufficient for basic tasks. However, recording 4K video at 60 fps is not supported, and this hardware configuration will not be enough for demanding games.

We have collected the results of smartphone testing, conducted using the latest versions of popular benchmarks, in convenient tables. Several other devices from different segments, tested on the same versions of benchmarks, have also been added to the tables for a more visual assessment of the results. Unfortunately, it is impossible to present data from different versions of benchmarks within one comparison, so many current models that were tested on previous versions of programs remain «behind the scenes».

We test for performance degradation when heating using the Burnout Benchmark program, which allows you to load the CPU, GPU and NPU:

The Cubot X90 smartphone is equipped with a 5100 mAh battery and, as expected, shows low autonomy in tests. The MediaTek platform, familiar and quite outdated, has never been distinguished by a high level of energy efficiency.

Testing was carried out at a standard level of energy consumption, without using energy saving functions, although such capabilities are available in the device. Test conditions: minimum comfortable brightness level (about 100 cd / m²). The tests included endless reading in Moon + Reader (with a standard light theme), continuous viewing of HD video (720p) and the game Injustice 2 with automatic graphics settings.

All these are the maximum possible figures obtained in “ideal” conditions, including without SIM cards installed. Any changes in the operating scenario will most likely lead to worse results.

The smartphone charges in about 1.5 hours from the included network charger.

The Cubot X90 smartphone is a typical second-tier Chinese device that tries to stand out thanks to a curved AMOLED screen with a refresh rate of 120 Hz. However, low brightness and other shortcomings of the implementation do not allow us to call the screen really high-quality. The 100-megapixel camera is also disappointing. The design of the device is impressive, and the body materials look decent, but the internal filling is budget. Performance, connectivity and battery life are average.