Oukitel U13 Review

At the beginning Oukitel U13 was announced as the U13 Pro. Afterwards the manufacturer decided the U13 is more appropriate for its latest flagship, but delayed its production until recently. This new smartphone marked the end of 2016 and the beginning of 2017 for the company. Besides being the latest model from the U series it is also one of the most feature-packed smartphones of this manufacturer. Usually Oukitel devices are reasonably priced with a good price-to-quality ratio and below we will check this precisely.

Specifications

Oukitel U13 is equipped with an IPS display that has a 5.5-inch diagonal size, a 1080p resolution and a 2.5D curved glass cover. It graces an aluminum alloy unibody, available in grey, silver, rose- and champagne gold colors. As long as it concerns the hardware, it is based on the currently rather old 64-bit MediaTek MT6753 chipset. It is manufactured after the 28nm process and includes eight Cortex-A53 CPU cores clocked at 1.3GHz and a tri-core ARM Mali-T720 MP3 GPU clocked at 450MHz. The on-board single-channel, LPDDR3 RAM measures 3GB and is clocked at 666MHz. The built-in memory is 64GB and can be expanded. There's a hybrid dual-SIM tray for that purposes, which houses either two micro-SIM cards, or a micro-SIM card and a microSD one for additional storage space. The smartphone supports quad-band 2G GSM, dual-band 3G WCDMA and penta-band 4G LTE Cat. 4 networks. The on-board sensors are limited to proximity, light and accelerometer ones, however, there's an IR blaster that turns the device into a convenient remote control of household appliances along with a feature-rich fingerprint sensor as well, placed on the back of the device. It is accompanied by a 13-megapixel camera with an AR1335 sensor by ON Semiconductor coupled with a dual-LED flash. It is software interpolated to 16 megapixels. The front facing camera is equipped with an 8-megapixel OmniVision OV8856 sensor, which is software interpolated to 13 megapixels. The 3000 mAh Li-Pol battery on board is non-removable and arrives with a standard 5V/1A charger. A complete list of the specifications of Oukitel U13 can be found here.

What's in the box

U13 arrived in a traditional Oukitel box with a rectangular, pristine white body and a bright orange lid with the company's logo imprinted in gold on it. On the back as per standard some data about specifications and certifications is provided. Once you open the box you get immediate access to the phone and in the compartment below it you'll see the SIM tray pin, charger, USB cable, warranty card, a short user manual and a transparent silicone case for protecting the back and frame of the smartphone.

Design and build

The all-metal unibody is one of the focus points of U13. The device is crafted from a single slab of aluminum alloy. Usually Oukitel are very meticulous in their manufacturing and build processes, and this model is no exception. The matte back flows into the glossy chamfered rear edges that merge with the frame, which on its part is merged with the glossy chamfered edges at the front. The display case tightly fits the frame and has a 2.5D curved glass finish for enjoyable touch experience. It is widely known that this type of design requires a different approach to placing the antenna bands, so the metal material won't hinder connectivity. The U13 has its antenna bands placed in a similar fashion to those of HTC 10 and the OnePlus 3. Actually, the overall design is largely reminiscent of the design of those two smartphones. However, the U13 bands are made of hard plastic (not the rubbery material used in other smartphones we've reviewed) and slightly protrude from the rear surface of the device. The model is available in dark grey with a black front and champagne gold with a white front. We are reviewing a champagne gold unit. The color is subtle and nice. The contrast with the white antenna bands is quite striking to us, but thankfully, they are thin, and are not as bold as those of the iPhone 6, for example. Just like in the U20 Plus, U13 has the volume and power buttons placed on its left frame for a change. However, the volume button is a single one for up and down, while the U20 Plus has two separate buttons for volume up and down. On the right frame, the hybrid dual-SIM tray is positioned. On the top frame you will see the 3.5 mm jack and the infrared emitter, while on the bottom one, there's a micro-USB 2.0 port with speaker grilles on both sides and a hole for a microphone to its right. The single speaker on board is hidden behind the left grille. On the back, centrally along the vertical the primary camera is positioned. It has a square module with rounded corners that slightly protrudes and is surrounded by a chamfered glossy rim. To its right the dual-LED flash appears. Below the camera is the square fingerprint sensor with rounded corners, which is "debossed" on the back and has a chamfered glossy rim, too. Above the bottom antenna band you will see the Oukitel logo and website. From left to right the front-facing camera, earpiece, LED notification light, light and proximity sensors are placed above the screen on the front of the smartphone. Below it there's only empty space as the navigation bar is software only. You can switch the menu and back buttons' positions as well as opt for the bar to hide from the corresponding Settings menu. The frame around the display is extremely thin due to the all-metal unibody design, but the black bezels around the display are very thick. Because of this the width of the smartphone is below the average for a 5.5-inch device - 75.6 mm, but is not extremely narrow. The height however, makes it quite a compact device. The 149 mm are well below the average for a smartphone with that size-class of a display. U13 is 8.1 mm thin and weighs 156.7 grams, which is typical for a smartphone with a 5.5-inch screen and a 3000 mAh battery.

Display

Oukitel U13 features a 5.5-inch display with an IPS panel that has a resolution of 1080 x 1920 pixels and is covered with a 2.5D curved glass. The black bezels are quite thick and cannot pass unnoticed. The manufacturer does not specify the type of protective glass, if there's any. The unit we have received showed a peak brightness of 449 cd/sq.m. This is an OK level for indoors, but outdoors under direct sunlight it might not be enough for comfortable viewing. The white luminance values start to drop more significantly at 50% of brightness, and so do the black luminance values. The decrease in the two is very proportional, which leads to a steady static contrast ratio of around 1000:1 at all brightness levels. With these white luminance values, the contrast could be higher, but the black luminance values are high, hence the contrast is an average one. The temperature of the white point exceeds 11000 K at all brightness levels, meaning colors look rather cold. This is a typical characteristic of Oukitel smartphones.

Brightness	White luminance	Black luminance	Contrast	Color temperature
100 %	448.953 cd/m2	0.453 cd/m2	991 : 1	11220 K
75 %	420.677 cd/m2	0.420 cd/m2	1002 : 1	11236 K
50 %	294.903 cd/m2	0.291 cd/m2	1013 : 1	11267 K
25 %	163.336 cd/m2	0.162 cd/m2	1008 : 1	11310 K
0 %	22.27 cd/m2	0.022 cd/m2	1012 : 1	11606 K

The CIE diagram below demonstrates that the panel does not cover 100% of the sRGB color space. The colors deviate in the blues area, while the full range of reds and greens cannot be displayed. The sub-pixel geometry of the panel is traditional - striped. The viewing angles are not bad if you look at the color reproduction only, however, there's quite a noticeable loss in brightness when the display is observed from aside.

OS, UI and software

In terms of looks and feel the UI on U13 is the closest you get to Android 6.0 Marshmallow compared to any other Oukitel smartphone out there. Clean and fast, it offers no clutter and works swiftly. All the standard UI features are present and left almost intact. These include the lock screen that contains a shortcut to the Dialer and Camera app and the home screen, which contains a row of docked apps at its bottom and a row of most used ones. The first contains the Dialer, Contacts, App Tray, Messenger, and default Browser. The row of favourites contains the Camera, Music, Play Store, and Settings. You can remove the clock widget from the home screen, if you want to and rearrange the icons as you please. The apps are accessed either by swiping to the left to access a successive screen or by the App Tray. If accessed by the tray, they appear in alphabetical order on one screen that can be scrolled downwards. The Notifications and Quick Settings shades are classic. The latter allows you to activate the System UI Tuner by tapping and holding on the Settings icon. The other icon next to it opens the Add a contact feature. The Volume and Power off shades are typical for the UI, and unlike in previous Oukitel models the Power off contains a Quick Reboot feature, instead of a Super power saving mode. A tap on the menu button opens the Task Manager with a Clear all function. A tap and hold anywhere on the empty space on the home screen opens the Widgets menu. Besides the standard set of widgets and a shortcut to the Settings, it contains a Themes option that allows you to choose from three pre-installed themes and a plethora of wallpapers - static ones for the lock and home screens, and a separate tab for the live ones. The Settings menu is quite traditional and enriched with somatosensory and gesture-related options. As usual, it starts off with the Wireless & networks menu, from where you can adjust your Wi-Fi connections, Wi-Fi Direct and Wi-Fi Hotspot settings, Bluetooth and Tethering options, manage your SIM cards and data usage. The second major Settings group is called Device and begins with the Display menu. Among all else, the latter contains a toggle for opening the flash upon receiving a call, options for the LED notification light, navigation bar settings, font size. The Display menu is followed by the Gesture Motion one, which includes two groups: telephony (flip the phone to silence a call and swing the phone to answer a call) and system motion with five options some of which are the ability to make screenshots by swiping three fingers on the screen, double tap to lock, etc. The Sound & notification settings offer the usual sound profiles, DND mode options, app notifications management and sound enhancement. They are followed by the App menu that offers settings for each and every app stored on the device with some additional options such as app permissions and links, drawing over other apps, etc. The following menus include Storage & USB, Battery, and Memory. While those regarding the storage are obvious, we will discuss the battery ones in the Battery section of this review. The Device group of settings also contains a first-time feature on an Oukitel device - Parallel Space. It works in a similar fashion to Xiaomi's Second space in MIUI 8. By creating a virtual machine, this feature allows you to maintain two different spaces in one device. Thus you can keep your information private, separate your work from your private life, manage several accounts for one and the same app more easily. The last feature of the Device group is the Gesture unlock. By drawing a simple sign on the screen when it is turned off opens up a corresponding app. The third major group of settings is called Personal and starts with Location, while the second menu is the Security one. It is quite extensive and besides all else contains quite a choice of screen lock type, including Voice unlock, a Fingerprint calibration function and Smart Lock options. Once you set up a screen lock different from swipe, the Smart Lock settings are activated and you can choose your device to stay unlocked while it is near your body, trusted places, devices, or voices. This also activates two other options - automatic lock countdown and a power button instant lock toggle, which is switched on by default. The Fingerprint settings are listed as a separate sub-group because they are richer than average. For starters, you can assign various tasks to your fingerprint IDs. Besides unlocking the phone, an ID can be assigned to unlock certain apps that are locked. By using your fingerprint you can take photos, answer calls, browse photos in the gallery, play music and videos. When you click on a fingerprint ID that is already stored you can edit its name or delete it, but you can also access a list of applications, which you want this ID to be applied to. The Personal group of settings also contains an Accounts menu along with a separate Google account one, Language & input, Backup & reset. It is followed by the fourth and last main Settings group - System. It contains the usual Date & time, Schedule power on & off, Accessibility, Printing, Developer options, and About phone. However, there is one additional menu called Smart somatosensory. It offers you to interact with the phone from a distance only by using gestures. For example, you can browse photos in the Gallery, take photos with the Camera, play music, dial or answer calls automatically. If you have activated the System UI Tuner, it will appear as the last menu in the Settings. It contains the usual options for editing the Quick Settings toggles, switching on/off icons appearing in the status bar, a toggle for showing the embedded battery percentage, and the Demo mode. As mentioned earlier, the way the apps appear on U13 is the closest thing you get to a classic Android M appearance on an Oukitel smartphone so far. If you are accustomed to their way of listing apps - they have left this option, too - the new apps appear on successive screens accessible directly from the desktop by swiping to the left. The good thing about UIs from this manufacturer is that they come with almost stock variants of the classic OS and have Play Store pre-installed along with a bunch of other default Google/Android M apps such as Gmail, Google, Maps, Voice Search and YouTube. Of course you get the classic Dialer, Contacts, Messenger and default Browser. The Calendar, Clock, Calculator, and Sound Recorder are also Android 6.0 stock applications along with the Downloads, Email, File Manager, and Gallery ones. U13 arrives with an FM Radio app, AppLock, Themes, Wireless Updater, ZaZa Remote and Parallel Space apps. As long as it concerns the ZaZa Remote app, we tested it and it worked fine in detecting a local TV and turning the smartphone into a remote control for it via the built-in infrared emitter. The Parallel Space app does everything the corresponding menu in the Settings does.

Networks, calls and connectivity

Oukitel U13 is equipped with a hybrid dual-SIM card with two slots for micro-SIM cards. The second can also house a microSD card, in case the on board 64GB are not enough for you. One of the slots supports only 2G GSM networks, while the other works with quad-band 2G GSM (850, 900, 1800, 1900 MHz), dual-band 3G WCDMA (900, 2100 MHz), and penta-band 4G LTE-FDD Cat. 4 (800, 900, 1800, 2100, 2600 MHz) networks. The unit we are reviewing offers excellent call quality even in remote areas and did not experience any issues in this regard. It is the same with the wireless connections. Even in areas where the Wi-Fi signal is generally weak, the device manages to maintain a stable connection with a good transfer rate. The model supports Wi-Fi 802.11 a/b/g/n, Wi-Fi Hotspot, Wi-Fi Direct, and Bluetooth 4.1, all of which work fine. The smartphone is equipped with a micro-USB 2.0 port, an infrared port and supports HotKnot - MediaTek's reply to Qualcomm's NFC. U13 works with GPS and GLONASS satellite positioning systems and the AndroiTS test shows that it manages to detect quickly satellites from both with a very good accuracy.

Performance

U13 is based on a 64-bit MediaTek MT6753 chipset, manufactured after the 28nm process for "super mid-range" mobile devices. It features eight ARM Cortex-A53 CPU cores clocked at 1.3GHz and a tri-core ARM Mali-T720 MP3 GPU clocked at 450MHz. The same system-on-chip powers the Oukitel K6000 Pro, Leagoo Shark 1, THL T7, UMi Touch, and Elephone S3. With an AnTuTu score of 40807 points, Oukitel U13 outperforms all of the above, which score 38500 points and lower. It is the same with the Geekbench 4 test (which is more strict than its previous version) and the Basemark ones, in which our review unit scored 603 points (single-core), 2441 (multi-core) and 8684 points, respectively. The picture is the same if you compare the results from the 3DMark and PCMark benchmark tests. The U13 outperforms the above mentioned models in those. This does not mean that heavy graphics game will be flawlessly fluent at their highest graphics settings. In practice those difference might turn out to be only marginal as long as it concerns graphics. There are 3GB of single-channel RAM clocked at 666MHz. The RAM is of the older generation - LPDDR3, so it is not as fast as memories from the newer LPDDR4 one, but this does not effect performance in a way that you can feel in day-to-day of the smartphone. The internal memory measures 64GB and can be expanded via a microSD card, if you're ready to sacrifice the second slot in the SIM tray. Of those gigabytes on board, 54GB are available to the user. The Androbench results point at it being an eMMC type of memory, but nothing is officially specified in this regard. The group of sensors is quite basic and includes a proximity, light, and accelerometer sensors. There's a rear-mounted fingerprint sensor on board as well. It offers a plethora of functions and is very quick in unlocking the device from a switched-off screen.

Cameras

The Camera app is the standard Android 6.0 one. Its home screen contains a video and shutter buttons, a shortcut to the camera settings, gesture-shot, HDR, flash, and camera-switch shortcuts. The settings for both cameras are one and the same, the only difference being the available photo resolution and video quality. There is a standard set of editing options as well, which include applying filters, adjusting frame position, editing the saturation, contrast, exposure, and so on.

Primary camera

The primary camera of Oukitel U13 is equipped with a 13-megapixel AR1335 sensor by ON Semiconductor. This is the first smartphone we review and the first we currently know of having such a sensor. On Semiconductor is headquartered in Phoenix, Arizona with sales points, design centers, and production facilities in North America, Europe, and the Asia Pacific regions. It has entered the image sensors market in 2011 with the acquisition of the CMOS Image Sensor Business Unit from Cypress Semiconductor. The AR1335 sensor is a 1/3.2-inch CMOS sensor with a resolution of 4208 x 3120, and a 1.1µm pixel. In U13 it is software interpolated to 16 megapixels (4608 x 3456). The camera can record FHD videos at 30 fps and is aided by a dual LED flash. The photos our review unit made lacked focus, while shooting landscapes. We have found a workaround this - if you focus on an object that's very near to you and immediately after that point the camera to shoot a landscape - the focus is fine. We can only hope that this can be fixed with a software update, because we have experienced a similar problem with another smartphone we have reviewed and this was fixed after an update.

Secondary camera

The front-facing camera of the model features an 8-megapixel OmniVision OV8856 sensor. Other smartphones that we have reviewed and use the same sensor for their front cameras are the Zopo Speed 8, ZTE Axon 7, Asus ZenFone 3 ZE552KL, and LeEco Coolpad Cool1 dual. The camera makes photos with a resolution of 3264 x 2448 pixels, but the sensor is software interpolated to 13 megapixels, so the photos are with a resolution of 4160 x 3120 pixels.

Audio

You can listen to music with the default Android 6.0 Music app. It does not have many features besides various types of sorting audio files, a standard equalizer and the standard playing options and playlist (shuffling, looping, etc.). The U13 unit we tested scored Very good as an overall result from our audio test. But we need to specify that most of the times there are nuances that make one Very good result better than another Very good one. In this case, we have a smartphone that excels only in frequency response. Important parameters such as THD, THD + Noise, and IMD + Noise score Good, Average, and Good, respectively. The combination of these three results is well below average. The rest of the parameters are rated as Very good, and so is the overall final result. The audio test is performed by using the TASCAM US-2x2 audio interface and the RightMark Audio Analyzer software. The speaker of the model is worse than average. It is located to the left of the micro-USB port at the bottom of the smartphone.

Test	Value	RMAA rating
Frequency response (from 40 Hz to 15 kHz), dB	+0.03, -0.11	Excellent
Noise level, dB (A)	-93.8	Very Good
Dynamic range, dB (A)	93.7	Very Good
THD, %	0.011	Good
THD + Noise, dB (A)	-76.5	Average
IMD + Noise, %	0.022	Good
Stereo crosstalk, dB	-76.0	Very good
IMD at 10 kHz, %	0.018	Very good
General performance		Very good

Battery

U13 is powered by a 3000 mAh Li-Pol battery that is non-removable and has a standard 5V/1A charger. The device has a separate PowerSaver app, which complements the standard settings of the Battery menu. The application includes toggles for a Power saving mode and a Smart-saving mode, a Power monitor and Protect Apps settings. When you switch on the Power saving mode toggle you can choose from a Smart power mode, Super power and Long standby mode. In addition, the Battery menu from the Settings provides a battery monitor with toggles for Super intelligent power saving and Battery percentage, along with data about which hardware part and software function consumes the most power. Of course, there are a Battery saver, Battery optimization settings, and Schedule power on & off. The graph below is our standard demonstration tool for the development of the charging process (yellow line) and the battery temperature (red line) over time. The standard 5V/1A chargers provide steady charging speeds and are gentle on the battery, and the U13 is no exception. The charging speed remained the same till the battery reached 90% of its capacity (2 hours and 25 minutes). Afterwards it dropped and the last 10% needed 30 minutes to charge. The whole process needed 2 hours and 55 minutes. As long as it concerns the battery temperature, the process started with the temperature being 34°C. When the battery reached 50% of its charge the temperature dropped slightly. At 90% it reached 30°C and at the end of the charging it was 28°C. The PCMark Work battery life 2.0 test showed a result of 4 hours and 53 minutes, which is a bit disappointing for a 3000 mAh battery.

Final thoughts

Oukitel U13 currently retails for USD 130, which is quite affordable for a smartphone with a full-metal unibody and a 5.5-inch FHD display. It has an excellent build, elegant looks and reasonable performance. The cameras and audio are not perfect, but are normal for a smartphone of that price class. All in all, the price-quality-ratio of this model is very good.