When to Choose Emulators over Real Devices?
By Tom Collins, Community Contributor - August 7, 2023
According to the Digital Journal, top companies worldwide use Android emulators, such as – Android Studio, Archon, LDPlayer, BluStack, and more, in their SDLC models. But what about the real devices? Are they being replaced in this ecosystem?
Well, the answer here is more than a simple yes or no. Instead, you need to understand the role of each device and its usage, along with how does an emulator work and when it is getting preference over real devices, to make an informed decision.
- Key Difference between Emulators and Real Devices for Testing
- Understanding the Concept of an Emulator
- How Does an Emulator Work?
- Scenarios for Choosing Emulators over Real Devices
- 1. Early-stage Development and prototyping
- 2. Testing across multiple device configurations
- 3. Replicating specific hardware or software conditions
Key Difference between Emulators and Real Devices for Testing
|Testing on emulators can’t give accurate results because it can’t replicate user-specific conditions from the target device. Thus, they tend to give error-prone results for the UX level testing.||Real devices on the cloud give accurate UX-level testing results, such as swipe, zoom, scroll, push notifications, phone calls, Bluetooth, etc.|
|Performance testing is unreliable with the emulators. They can’t replicate the processor’s speed, battery usage, memory usage, and other performance-specific issues from the original device. Moreover, they eliminate minor issues without any reporting.||Real devices efficiently produce accurate results for performance testing.|
|Emulators give some basic insight and analytics for the app’s performance.||But you can observe the in-depth performances of your apps. It will show you every step of your app’s behavior.|
|Geolocation and Localization testing is impossible with the emulators because they can’t emulate your device’s GPS, network, currency, and time zones.||You can quickly go for Geolocation testing and localization testing through the real device.|
|You can install an emulator instead of a low-cost or free of cost.||Purchasing a real device is costly compared to the emulators. Moreover, if you maintain a device lab for your testing, it will become expensive.|
Also Read: Difference between Emulator and Simulator
Understanding the Concept of an Emulator
Emulators are software programs or hardware that replicate the behavior and functionalities of other systems. For example, Android Studio can replicate several Android apps and let them run on your machine. You need a host machine to launch and run the emulator. Then, the emulator replicates the features of another system called the guest machine. This technique is known as emulation.
Also, these emulators are much more significant for mobile testing. They emulate the software and hardware of the target mobile device on your host machine. They translate the target device’s ISA (Instruction Set Architecture) to replicate it. You need to test your mobile through binary translation.
How Does an Emulator Work?
There are two types of emulation technologies – low-level emulation (LLE) and high-level emulation (HLE). You can choose any one from them.
The LLE mimics the hardware’s behavior of your device. The host computer replicates an environment to execute the LLE program. The HLE emulates the software- specifically, the functionalities of your device instead of the hardware. It performs three types of operations –
- Interpretation: The emulators replicate your system’s code line by line, follow every instruction, and execute them. However, it is a slow process where the emulator decodes each instruction and executes accordingly.
- Dynamic recompilation: The emulators examine the app’s machine instructions to process them more efficiently on the host’s processor. It executes specific instructions and runs the cached code.
- Lists interception: Some co-processors need primary processors to execute their instructions. The emulators also replicate these instructions. It is a list of commands that advises the coprocessor on what to execute. The emulator converts the command list in such format, which the coprocessor interprets.
This is how emulators work.
Emulator Architecture and Components
The emulators have three components: a CPU simulator, a memory unit, and an input/output device.
- The CPU simulator interprets the emulated application code, encodes it, and executes the instructions.
- The memory unit imposes memory-mapped I/O. It has two procedures to read and write from the logical memory unit.
- The I/O device consists of a unified I/O API. As the emulators never mimic the primary system bus, the I/O device is treated as a special module.
Emulator Software and System Requirements
To run an emulator these are the system requirements
- Operating system: Any OS – Windows, macOS, Linux, or Chrome OS. Your OS should be 64-bit.
- 16 GB RAM
- 16 GB disk space
Before learning emulator testing, you should know how to use emulators. You should follow these steps:
- Set up the environment for the testing and verify the system requirements.
- Create an AVD (Android Virtual Device).
- Run the application on your emulator.
- Perform general UX testing and navigate the emulator’s screen
Benefits of Using Emulators
- Cost-effectiveness and accessibility” Most emulators are free and open-source. So you can easily download them for your testing.
- Useful in the early stage of SDLC: They are suitable for the early stages of the SDLC, such as unit testing.
- Reproducibility and Consistency: They maintain consistency within your mobile application through the early stages of development. They help the developers and testers identify the bugs as earliest as possible. So, it protects your application from a major breakdown in the later stages.
Limitations of Emulators
- Performance and Speed Differences: Emulators need enough disk space on the host machine otherwise, they may crash. Emulators don’t always give accurate results when it comes to performance testing. Additionally, its low pace differs significantly from real devices, at times, it also glitches with hardware optimization and loss of software.
- Variability in Real-world Device Behavior: Depending on an emulator for real-device behavior, such as – battery drainage, memory usage, sensors, etc., is impossible as it can’t simulate hardware performance and lacks disk control.
- Incompatibility with specific apps or use cases: Emulators are incompatible with some specific apps. In that case, you will see an incompatible status when you try to install the app on your emulator. They tend to perform poorly if you’ve installed antivirus or any security software on your computer.
Scenarios for Choosing Emulators over Real Devices
1. Early-stage Development and prototyping
Emulators are the best for unit testing. They can debug and execute your application’s code faster. So, you can save lots of costs by using emulators in the earliest stages. Also, the emulation capacity of the emulators helps to make the prototypes for complex software designs and verifications.
2. Testing across multiple device configurations
The emulators can test different OS versions for Android and iOS devices. Moreover, you can download them on different desktop OS – Windows, Linux, macOS, etc.
3. Replicating specific hardware or software conditions
The popular emulators can replicate high-quality gaming applications and some specific hardware conditions.
When to choose Real Devices over Emulators?
1. Remote Testing
To offset the challenges of remote testing, you can use emulators. You can do it at a low cost. But if you’re planning for performance, regression, responsive, sanity, UAT, and UX testing, you must choose a real device cloud.
2. No Need to Maintain Device Farms
You should use emulators when you do not want or need to maintain a device farm. Generally, emulators are lower priced than physical devices. Hence, you can use emulators to cut the cost of lab management. The second option is using a real-device cloud for mobile testing.
3. Updated Flagship iOS and Android devices
You must use real devices to get the updated versions of iOS and Android. With the updated OS versions, you can test the new features of your mobile devices. The emulators are not compatible with the latest version of iOS and Android.
You must consider the real devices to obtain the error-free result of user experience testing. The QA team always prefers to perform this testing with real user conditions and real devices. It helps your application reach the ultimate business requirement.
5. Compatibility with Native Device Features
You must test your native device features on the real device. It conveys the pin-pointed result for testing battery charging, camera, GPS, speaker, microphone, etc.
6. Validating Network and Connectivity issues
You can test the various network conditions, such as 2G, 3G, 4G, or Wi-Fi connection with the physical devices. You can test your mobile’s performance at high and low network speeds.
7. Geolocation Testing
You can easily perform Geolocation Testing using GPS and IP geolocation through your mobile device. This testing optimizes a result for a pre-defined geographical area. Thus, the real devices help you in localization, geotargeting, geofencing, geotagging, and geoblocking.
BrowserStack Device Cloud for Mobile Testing
- Omit the need for physical device labs and trim your development cost. With Live, you can test any device-browser combination and resolve device fragmentation.
- It provides a seamless experience of localization testing with the time zone, translation, and currencies.
- App Live supports testing from multiple sources, such as Play Store, App Store, Rest API, and more. Also, you can directly upload your app for testing.
- Access native device features for testing, such as network simulation, geolocation testing, push notification, and more.
Knowing how emulators work helps you to understand the difference between emulators and real devices. Choosing an emulator over real devices for your mobile testing also implies several advantages and drawbacks. Ensure to test on real devices for accurate results in your SDLC.