Comparison Samsung Galaxy Watch Active 2 44mm vs Amazfit GTR 47

The operating system installed on the gadget itself.

In this case, we do not mean basic firmware, but rather a full-fledged OS that provides extensive capabilities. For example, allowing you to install additional applications or functionally tailored for close integration with certain web services. The most popular operating system options for wrist gadgets are presented below:

– Android. The Android mobile OS is known mainly for smartphones and tablets, but its open source code allows it to be optimized for other devices, including wrist devices. Note that traditional Android applications are generally poorly compatible with wrist gadgets, but some programs are able to automatically adapt to such devices, and specialized software is also produced for certain models (often by the manufacturers themselves).

– WatchOS. An operating system specially designed for Apple wrist gadgets and used only in them. Among the key features, it is worth noting support for the Siri voice assistant and the Apple Pay system, a set of fitness tools, as well as a high degree of optimization for Apple Watch controls. WatchOS uses its own applications, which can also be created by third-party developers.

– Wear OS. The system formerly known as Android Wear. This is a specific version of Android, originally developed as a solution for “smart” wrist gadgets. It features a radically redes...igned interface, close integration with the Google Assistant voice assistant, and so-called proactive notifications. Thanks to the latter, the device is able to independently, without a request, issue extended tips for a certain situation: for example, before an important meeting, plot a route on the map taking into account traffic jams and, if necessary, turn on a reminder earlier than the originally planned time.

— Nucleus. Quite a rare and unusual “OS”: it does not belong to a general-purpose OS, but to real-time systems. Such systems are optimized for the fastest possible response to external events (whereas in conventional operating systems the reaction occurs depending on the distribution of resources). Specifically, Nucleus has all the capabilities necessary for wrist gadgets, however, for a number of reasons, such firmware is quite rare.

— Tizen. An open operating system for mobile devices, primarily promoted by Samsung. As with Android, the original Tizen is poorly suited for smartwatches, so we usually talk about a special version of Tizen Wearable. It is worth noting that there are tools that allow you to run Android applications on devices running this OS.

– ColorOS. A system developed by OPPO and used in its mobile devices. Directly for smart watches, the operating system is presented in the form of ColorOS Watch - the system interface is optimized for use on small screens and includes tools for tracking the user’s physical activity, monitoring sleep and health, managing notifications, etc. Moreover, smartwatches powered by ColorOS Watch can serve as a digital key for some modern Chinese-made cars.

– HarmonyOS. Huawei's universal operating system, also known as Hongmeng. Provides operation of a wide range of devices: equipment from the smart home ecosystem, smart watches, smartphones and tablets. Onboard wearables, HarmonyOS is a redesigned version of the homegrown Lite OS used in Huawei watches and other low-end devices.

– Zepp OS. A specialized real-time system for Amazfit and Zepp smartwatches. It is an open platform for health management and activity tracking, based on the principles of ease, fluidity and practicality. One notable feature of the OS is support for cloud Internet service applications (like Spotify, SoundCloud, etc.).

– Lite OS. A lightweight system for wearable gadgets with limited computing power, used in some simple smartwatch models from Huawei. A more advanced version of the operating system for such devices from the manufacturer is HarmonyOS (see above).

– Fitbit OS. An operating system developed for Fitbit wrist gadgets and used only in them. Fitbit OS supports the installation of various applications on smart watches, the system implements gesture control, and many widgets and watch faces have been released for it. The operating system also provides targeted exercise modes and the possibility of contactless payment for purchases in stores using the NFC chip of the watch using the Fitbit Pay program.

– Moto Watch OS. Proprietary software for Motorola smart watches from the category of real-time systems. Moto Watch OS is designed with an eye toward accurate health tracking, the OS also collects information about user activity, supports receiving notifications from a connected smartphone, and ensures maximum battery life for the wearable gadget. Note that the operating system does not support installing applications from third-party developers - you will have to be content with pre-installed tools and programs.

– MagicOS. An operating system specially designed for Honor wrist gadgets and used only in them. In appearance and in terms of its set of capabilities, it is very similar to the related operating system HarmonyOS, which is found in Huawei wearable devices. It is argued that MagicOS has its own philosophy and development vector.

– BlueOS. Vivo's own OS, which can run a wide range of devices - from mobile phones and tablets to smart watches. In fact, the system’s debut took place on board wearable gadgets in 2023. The “operating system” is written in the Rust programming language with an emphasis on maximum protection of user data. A distinctive feature of BlueOS is generative artificial intelligence. Thus, Vivo smart watches have already implemented the function of creating dials by voice with the participation of AI.

– HyperOS. A unified Linux-based operating system for Xiaomi smart devices. But if in mobile phones HyperOS has replaced the proprietary MIUI shell, then in the smartwatch segment this is something new. The emphasis in Xiaomi's operating system is on the close interconnection of all devices running HyperOS within a single ecosystem.

Types of notifications, as well as basic voice communication features supported by the gadget.

- Notifications. In classic smart watches and fitness trackers, the specific functionality of such notifications can be different – from a regular sound or vibration signal to the ability to display on the screen and even respond. But in any case, such notifications are often more noticeable to the user than the own signal from a smartphone located deep in a pocket or bag.

— Voice control. The ability to control the device through voice commands. In order for a smartwatch or fitness tracker to perform some simple feature, it is enough to say its name aloud.

— Voice assistant. In watches with voice assistant support, the level of user interaction with the device is displayed in a new qualitative way. The most popular virtual assistants are Google Assistant and Amazon Alexa. In Apple devices, the role of an assistant is performed by Apple Siri, in Samsung wearable gadgets — a virtual assistant Bixby. Unlike the voice control function, the assistant does not just turn on this or that feature, but allows you to perform certain operations in applications that require feedback.

— Sound signal. The ability to give sound signals using the built-in speaker. This feature will be useful primarily in situations where the gadget is not on hand — for example, if it is used as an ala...rm clock and is removed at night.

— Vibration. Vibration signal similar to that used in mobile phones. In wearable gadgets, such a signal is especially convenient due to the fact that the device is constantly in contact with the wearer's skin, so that the vibration is perfectly felt — and regardless of the level of noise around. In addition, vibration mode is also useful in quiet environments where a loud sound signal is undesirable.

— Built-in microphone. Own microphone built into the body of the device. Such equipment can be used for different purposes, depending on the type and features of the gadget. First of all, voice communication is impossible without a microphone. Another feature for which a microphone is required is the voice assistant (see above). And in children's smartwatches, it may be possible to remotely turn on the microphone from the parent gadget and listen to what is happening around the child; see the relevant paragraph below for details.

— Speakerphone(speaker). The ability to work the gadget in hands-free mode, using the built-in speaker and microphone for conversation. In a conventional smartwatch (see "Type"), this feature allows you to talk through the watch without removing the smartphone from your pocket; in watch-phones, speakerphone allows you to do so without headphones and headsets, and for children's smartwatches, this feature is almost mandatory. However the volume of the built-in speaker is usually low, so in a noisy environment its power may not be enough.

Types of sports and medical data collected by the gadget (plus some features of a similar purpose, such as sleep tracking, smart alarms, stress levels and women's calendar). Note that the features from this list can be found not only in specialized fitness trackers (see "Type"), but also in more traditional devices like smartwatches. Here are the most popular options:

— Pulse rate. Heart rate is one of the most important physiological parameters of a person. So that sports training is as effective as possible, the heart rate must be in a certain range (the specific value depends on the purpose of the training and the personal data of the user). And for some illnesses and treatments, a faster or slower heart rate can be an important signal, including a warning of danger.

— Pressure (tonometer). A sensor that measures the user's blood pressure. Note that the accuracy of such a sensor is usually quite low, the measurement error can be 10% or even more; so it will not replace a full-fledged medical tonometer. On the other hand, a gadget with this feature is quite capable of detecting a critical increase or decrease in pressure, which will allow you to take the necessary measures in a timely manner.

— ECG. A sen...sor that allows you to get detailed data about the work of the user's heart. Note that such a sensor is not a full-fledged electrocardiograph — in fact, it is an advanced type of heart rate monitor that can track the features of the heart rhythm. However, even this is enough to detect some dangerous phenomena — for example, atrial fibrillation, which at first is imperceptible to a person — and take appropriate measures in time.

— The blood oxygen. A sensor (the so-called pulse oximeter) that determines the saturation of the blood with oxygen (saturation); at the same time, the measurement is carried out by a non-invasive method — without punctures and other damage to the skin. Like most medical sensors in wearable gadgets, it is not accurate and is not a full-fledged medical device, but it is quite capable of responding to a critical decrease in the level of oxygen in the blood. It is believed that the presence of a pulse oximeter is relevant primarily for certain diseases, when saturation may decrease due to the disease itself or the characteristics of the treatment being taken. However, this feature can also be useful for quite healthy users who often travel at high altitudes — primarily climbers and aeronauts.

— Body temperature. The presence of a sensor for measuring temperature allows you to take measurements without the use of thermometers. Naturally, errors can occur, so a slight deviation from the norm may not be determined, but the device will easily fix a significant increase in temperature.

— T° of the environment. Even though smartwatches are worn on the body, the built-in sensors in them are usually designed to measure the ambient temperature. This information can be useful both for a general assessment of the surrounding conditions, and for specific purposes — in particular, weather forecasting. It is not uncommon for watches with this feature to also have a barometer (see "Navigation").

— Number of steps. The traditional pedometer is a feature for counting the number of steps taken by the user. These measurements usually use data from the accelerometer, and the results are quite accurate: most modern accelerometers are well calibrated and are quite capable of distinguishing tremors during steps from hand waves and other extraneous movements. The exception is trips in land transport: many wearable gadgets perceive shaking as steps, which should be taken into account when evaluating the results.

— Distance travelled. Measurement of the total distance traveled by the user. For this, either data from a pedometer or a GPS module are usually used (see "Navigation"); each option has its own merits. So, the pedometer is cheaper, it can be used even in rooms without windows, where the signal from satellites does not reach, and on simulators like treadmills, where the user does not move relative to the ground. GPS, in turn, gives higher accuracy, especially over long distances, and is not prone to false positives in vehicles. In some advanced gadgets, these methods can be combined — this is not cheap, but it allows you to combine the advantages of both options and achieve maximum accuracy.

— Movement speed. Determining the speed of the user's movement. As with distance travelled, measurement can be done in a variety of ways; see above for more details. Also note here that many gadgets with this feature are able not only to determine the current speed, but also to constantly record its value and display various indicators: the maximum achieved speed, the average value for training, etc.

— Energy spent (calories). Measurement of the number of calories burned by the user in the process of movement. These data are rather approximate, as they are calculated by indirect parameters (speed and range of movement, personal specs of a person, etc.). However, even this accuracy is quite enough to determine the overall effectiveness of training.

— The amount of fat burned. Measuring the amount of fat burned per workout. As in the case of calories (see above), the result of such measurements is quite approximate. However, in fact, absolute accuracy is not required, and fat loss data can be a powerful motivator.

— Activity time. A measurement of the total time during which the user is actively moving. In many models, such metering may provide additional options, such as fixing several periods of activity with breaks between them and determining the ratio between the time of movement and the time of rest.

— Smart alarm. An alarm clock that monitors the user's sleep phases and gives a signal to wake up at the optimal time for this. Human sleep consists of alternating phases, and waking up in the unfortunate phase creates a feeling of lethargy and fatigue, even if there was enough time to sleep. A smart alarm clock avoids such situations; its work is based on tracking the pulse, breathing rate and other parameters that differ depending on the phase of sleep. Note that the deviation of the signal from the set time can be up to half an hour, but this is usually a deviation towards an earlier rise. As a result, the risk of being late with a smart alarm clock is close to zero, and the lack of sleep time is compensated by the optimal moment of awakening.

— Sleep tracking. Sleep quality assessment is based on data from on-board sensors of fitness trackers or smartwatches. In particular, the heart rate monitor controls the number of contractions of the heart muscle, the accelerometer controls the user's movements. A blood oxygen sensor, if available on the wearable, improves the accuracy of sleep quality data collection. According to the readings of the sensors, the moments of entering and exiting the deep sleep phase are recorded. It is during this period that the restoration of the nervous system and the accumulation of energy for the coming day take place. In deep sleep, a person can completely reboot and gain strength, while in REM sleep, brain activity practically does not differ from the state of wakefulness. The sleep quality analysis feature helps you determine the best time to go to sleep and provides personalized recommendations to improve your night's sleep.

— The level of stress. The level of stress of the body allows you to evaluate the metric that determines the variability of the heartbeat — the difference in time between successive contractions of the heart muscle. Respiration rate, maximum oxygen consumption and excess oxygen consumption after exercise are also taken into account. The stress level score gives a clear picture of the user's experience during the day, however, the value of this parameter is in determining the most optimal body regimen for training. A high heart rate variability usually indicates you are in good shape for playing sports, while a low one can indicate fatigue, dehydration, or feeling unwell. All this directly affects the ability to train effectively. There are no clear units for measuring the level of stress — in smartwatches, the parameter is usually shown as a scale from 0 to 100, often indicating the number of hours the body is under stress and the time it takes to recover to a normal state.

— Women's calendar. The tool for tracking the menstrual cycle keeps abreast of the events of the expected dates of the menstrual period, allows you to determine the most favorable days for conception, helps to notice alarming symptoms in time and prevent many diseases in case of cycle disorders. Based on your total cycle length, the device calculates a predicted date for your next period. The women's calendar records cycle dates, fertility windows, and the day of ovulation. By adding your own notes to it, you can track fluctuations in sleep, appetite, fitness, mood changes and predict well-being for a particular day.

In addition to those described above, more specific types of measurements can be found in modern wearable gadgets.

A training programme for waterproof smartwatches or fitness trackers with water sports disciplines support. In swimming mode the wearable gadget determines the speed, distance and time of the swim, advanced instances of smartwatches measure the number of laps in the pool, calculate the frequency and efficiency of strokes in certain swimming styles. A personal assistant on the wrist evaluates the performance of water workouts and often makes recommendations to improve their effectiveness.

The size of the display installed in the gadget; for round screens, respectively, the diameter is indicated.

A larger screen, on the one hand, is more convenient to use, on the other hand, it significantly affects the dimensions of the entire device, which is especially critical for wearable gadgets. Therefore, manufacturers choose the display size in accordance with the purpose and functionality of each specific model — so that there is enough space on the screen and the device itself is not too bulky.

It is also worth mentioning that screens with a similar size may have different aspect ratios. For example, traditional smartwatches are usually equipped with square or round panels, while in fitness trackers, screens are often made elongated in height.

Screen size in dots (pixels) horizontally and vertically. In general, this is one of the indicators that determine the image quality: the higher the resolution, the clearer and smoother the picture on the screen (with the same size), the less noticeable are the individual dots. On the other hand, an increase in the number of pixels affects the cost of displays, their power consumption and requirements for a hardware platform (more powerful hardware is required, which itself will cost more). In addition, the specifics of using smartwatches is such that there is simply no need to install high-resolution screens in them. Therefore, modern wrist accessories use displays with a relatively low resolution: for example, 320x320 with a size of about 1.6" is considered quite sufficient even for premium watches.

The density of dots on the screen of the gadget, namely, the number of pixels that are on each inch of the panel vertically or horizontally.

The higher the PPI, the higher the detail of the screen, the clearer and smoother the image is. On the other hand, this indicator affects the price accordingly. Therefore, the higher the density of points, the more advanced, usually, this gadget is in terms of general capabilities. However, when choosing a screen, manufacturers take into account the general purpose and functionality of the device; so that even a small number of PPIs usually does not interfere with comfortable use.

The material from which the transparent cover of the display is made.

— Plastic. Inexpensive, moreover, quite durable and impact-resistant material: even with a strong impact, the plastic is more likely to crack than crumble into fragments. At the same time, scratches easily appear on such a surface, and over time it inevitably becomes cloudy. Because of this, plastic is found predominantly in inexpensive wearable gadgets.

— Glass. In this case, it can mean both classic silicate glass (the same as, for example, in windows), and some original types of impact-resistant glass that are not related to Gorilla Glass(see below). Regular glass costs more than plastic, but not by much, and it looks better and stays clear longer due to its scratch resistance. The main disadvantages of this material are fragility and a tendency to crumble into sharp fragments upon impact. Impact-resistant glass types are devoid of this drawback to one degree or another, but they are also more expensive. According to the price category of the gadget, you can quite accurately determine what kind of glass it uses — ordinary or shock-resistant.

— Sapphire. The coating made of synthetic sapphire is used exclusively in premium-class gadgets — this is due to the complexity of its production and, accordingly, the high cost. On the practical s...ide, sapphire is extremely scratch resistant (it is only possible to scratch such glass with a diamond or special tools), but at the same time it is fragile and easily breaks from impact.

— Gorilla glass. A family of shock-resistant glass types created by Corning and widely used in modern electronics, including wearable gadgets. In addition to strength, Gorilla Glass is also distinguished by good scratch resistance, while being relatively inexpensive (by the standards of such a coating), which has led to their popularity. However, the specific properties of such glass depend on its version; Here are the options that are relevant for modern wearable devices:

• Gorilla Glass v3. The oldest current version was released in 2013. Nevertheless, even such a coating is noticeably superior to traditional glass (not to mention plastic) in terms of transparency and scratch resistance.
• Gorilla Glass v4. Version released in 2014. A key feature was that the development of this coating focused on impact resistance (whereas previous generations focused mainly on scratch resistance). As a result, the glass turned out to be twice as strong as in version 3, despite the fact that its thickness was only 0.4 mm.
• Gorilla Glass SR+. The first version of Gorilla Glass, designed specifically for smartwatches and other miniature wearable gadgets; presented in 2016. According to the creators, the scratch resistance of such coatings approaches those of sapphire glass while maintaining the main advantages of Gorilla Glass — high strength and transparency. In general, for this material, superiority over "alternative options" is claimed by 70% in terms of strength specs and by 25% in terms of optical properties.
• Gorilla Glass DX. Another type of glass, specially designed for wearable devices. It was released in 2018 at the same time as the DX+ version (see below). Of the key improvements in Gorilla Glass DX, in particular, increased anti-reflective properties and an increase in the contrast level of the visible image by 50% are announced; the latter, among other things, allows you to reduce the actual brightness and, accordingly, the power consumption of screens without compromising image quality, which is especially important for miniature wearable devices. And this material differs from the DX+ type coating, on the one hand, by lower scratch resistance, and, on the other hand, by higher anti-reflective specs.
• Gorilla Glass DX+. Almost the same as the original version of DX, related to the same specialization — wearable wearable gadgets and other miniature devices. At the same time, DX + has a higher scratch resistance, but has slightly worse anti-reflective specs. Otherwise, these types of coverage are almost identical.

Bezel-less are displays in which the case or bezel does not occupy the usable area of the front panel, or it is minimized. In terms of design, bezels have both pros and cons. One of the most important reasons for adding substantial bezels to your screen is physical protection. The bezel-less display is very easy to scratch or damage when dropped. On the other hand, the frame takes up space on the screen, and this is one of the reasons why the frames in modern smartwatches are minimized, making the gadget more compact and stylish.