The internal memory of an Android-based smartphone is a fundamental data store, without which the operation of the device is impossible in principle. Unlike random access memory (RAM), which is erased when the power is turned off, internal memory retains the operating system, installed applications, photos, videos and personal files of the user even after the battery is completely drained. Understanding exactly how this storage works is critical to properly managing your smartphone and preventing it from slowing down over time.
Many users mistakenly believe that the gigabytes declared by the manufacturer are available for storing files in full. In practice, a significant part of the space is occupied by system partitions that are hidden from the eyes of the average owner. In addition, the physical nature of flash memory imposes certain restrictions on the write speed and durability of the cells, which directly affects the performance of the gadget in the long term.
In this article we will analyze in detail the architecture of the internal drive, consider the difference between the eMMC and UFS storage types, and also give practical recommendations for maintaining free space. You will learn why filling the memory to capacity can lead to critical failures and how to correctly distribute data between the internal memory and the microSD card.
Internal storage architecture: physical partitions
The physical memory chip inside your smartphone is logically divided into several independent areas, each of which performs a strictly defined function. The operating system Android uses a complex partitioning scheme to isolate critical system files from user data. This ensures stability: even if the user accidentally deletes important files in his partition, the system will be able to boot.
The main space with which the device owner interacts is the partition userdata. This is where all applications downloaded from the store are installed, cached game data is saved, photos from the camera and music are downloaded. The volume of this partition changes dynamically depending on how much space is occupied by system files in other, hidden partitions.
In addition to the user partition, there are areas system, boot and recovery. The section system contains the operating system itself and pre-installed applications that cannot be removed by ordinary means without obtaining superuser rights. The partition boot stores the system kernel and the bootloader required to start the device.
⚠️ Attention: Attempts to manually resize system partitions or delete files from folders that require root access can lead to the device being “bricked.” Without deep knowledge of the structure of the Android file system, it is strictly not recommended to interfere with service areas.
Modern devices use a file system ext4 or a newer one f2fs (Flash-Friendly File System), which is optimized specifically for working with flash memory. The choice of file system affects the speed of reading and writing small files, which is especially noticeable when running heavy applications or installing updates.
The f2fs file system is often found in flagship Samsung models and provides higher speed compared to ext4, especially when actively writing data.
Storage types: from eMMC to UFS 4.0
The speed of your smartphone directly depends on the type of internal memory chip used. In budget and older models, the standard eMMC (embedded Multi-Media Card) is still often found. Its main disadvantage is that it can only operate in one mode: it either reads data or writes it, but cannot do both at the same time. This creates a “bottleneck” when multitasking.
More modern devices are equipped with standard drives UFS (Universal Flash Storage). Unlike its predecessor, UFS operates on the principle of full duplex, allowing you to simultaneously read and write information. The difference in speed between eMMC 5.1 and UFS 3.1 can reach a tenfold value, which is instantly felt by the user when opening a gallery or installing games.
The evolution of standards is happening rapidly, and now the following main types of drives are on the market:
- 📉 eMMC 5.1 — the basic standard for budget smartphones, sequential read speed is about 300 MB/s.
- 🚀 UFS 2.1 / 2.2 — common in the middle segment, ensures comfortable interface operation and quick launch of applications.
- ⚡ UFS 3.1 / 4.0 —flagship solution that supports write acceleration and energy saving technologies, speeds can exceed 4000 MB/s.
When choosing a new phone, it is important to pay attention not only to the amount of memory (64, 128, 256 GB), but also to her type. A smartphone with 128 GB of memory based on UFS 3.1 will work much faster than a model with 256 GB on a slow eMMC, especially after a year or two of active use, when the storage is filled with fragmented data.
System files and hidden spaces
Why, after purchasing a new smartphone with a claimed 128 GB of memory, is only 110 GB available to the user, for example? The answer lies in the service needs of the operating system. Part of the physical volume is reserved for technical needs, and this process is not a manufacturer’s mistake or a marketing deception.
The system reserves space for the swap file, error logs, temporary update files and service recovery partitions. In addition, manufacturers often install their own add-ons over pure Android, which can take up from 5 to 15 GB of disk space depending on the brand and version of the shell.
| Partition type | Purpose | Approximate volume |
|---|---|---|
System |
Operating system files and shell | 8–15 GB |
Recovery |
Recovery and reset environment | 100–500 MB |
Cache |
Temporary data to speed up work | Dynamic |
Vendor |
Hardware drivers and specific software | 1–3 GB |
It is also worth considering the peculiarity of calculating the amount of memory. Drive manufacturers use the decimal number system (1 GB = 1,000,000,000 bytes), while the Android operating system uses the binary number system (1 GiB = 1,073,741,824 bytes). Because of this mathematical difference, the declared 64 GB in the system is displayed as 59–60 GiB even before installing any applications.
The difference between the declared and actual amount of memory is not a defect, but a consequence of different number systems and mandatory Android service partitions.
The impact of memory fullness on performance
There is a common misconception that a smartphone starts to slow down only when the memory is 100% full. In fact, the critical decline in performance begins much earlier. Flash memory requires free space for the controller and cell wear leveling algorithms to operate efficiently.
When free space is less than 10-15% of the total volume, the memory controller is forced to spend significantly more time searching for free cells to write new data. This process is called garbage collection (Garbage Collection). When there is a shortage of space, the system is forced to constantly rewrite blocks, which leads to noticeable “freezes” of the interface and long opening of applications.
In addition, when it is very full, the recording speed suffers. If you try to shoot a high-resolution 4K video on a nearly full phone, the recording may be interrupted or the frame will be skipped because the recording buffer does not have time to flush data to the physical media at the required speed.
⚠️ Attention: Constantly operating a smartphone with full internal memory (less than 5 GB free) accelerates the physical wear of the chip. Memory cells have a limited resource of rewrite cycles, and when there is a shortage of space, wear occurs unevenly and faster.
To maintain high speed, it is recommended to regularly free up space. You should not wait for notifications from the system about low memory. The optimal usage scenario is to keep at least 20% of the total storage capacity free.
Adaptive storage and microSD memory cards
Many mid- and budget-class smartphones support the installation of memory cards microSD. However, the way they are used dramatically affects the convenience and speed of work. In modern versions of Android, there are two main modes of working with external media: portable storage and internal memory.
In portable storage mode, the card is used as a regular flash drive. You can dump photos, videos and music onto it, but you cannot install applications there using standard means. This mode is convenient for transferring data between devices, since the card remains readable on other gadgets and computers.
Mode internal memory (Adoptable Storage) allows you to format the card in such a way that the system combines it with the main drive into a single space. In this case, you can install applications and transfer game data to the card. However, there are important nuances:
- 🔒 The card is encrypted and linked to a specific phone; you won’t be able to insert it into another device without formatting.
- 🐢 The speed of applications on a memory card is almost always lower than on the built-in UFS chip, which can cause slowdowns.
- 💀 If the card fails, data can be lost forever, since restoring an encrypted partition is extremely difficult.
Using a card as internal memory only makes sense if the built-in storage is critically small (for example, 16 or 32 GB), and the memory card has a high speed class (not lower than A2 / UHS-I). For flagship devices with fast built-in storage, this mode is usually not recommended.
Why are manufacturers abandoning microSD slots?
Refusal of memory cards allows engineers to make smartphones thinner, improve moisture protection and use space for a more capacious battery or an improved cooling system. In addition, this encourages users to buy more expensive versions with more internal memory.
Practical cleaning and optimization methods
When the internal memory space runs out, the user needs to act quickly and efficiently. Simply deleting applications often does not give the desired result, since the bulk of the volume is occupied by the cache and media files of instant messengers. For example, Telegram or WhatsApp can quietly take up tens of gigabytes over a year of correspondence.
For proper cleaning, you should use the built-in tools of the system. In the settings of most shells there is a “Storage” or “Memory” section, where the system itself tells you which files take up the most space. It is also useful to use the “Cache Clear” function for heavy applications such as browsers, YouTube and social networks.
Below is a checklist of actions for quickly optimizing free space:
☑️ Express memory clear
Another effective method is to transfer media files to the cloud services such as Google Photos or Yandex.Disk. These applications allow you to enable the function of automatically freeing up space: after uploading a photo to the cloud, it is deleted from the phone’s internal memory, remaining available for viewing via the Internet.
⚠️ Note: When using cleaning applications (Clean Master and analogues), be careful. Aggressive cleaning can remove important cache files, causing apps to take longer to launch the next time you open them because they have to re-download data from the network.
Regularly auditing your installed apps can also help free up space. Go to settings, sort apps by size and delete those that you haven't used in the last three months. Often, games after completion take up space only with their cached data, which can be deleted without erasing the progress itself (if it is saved in the account).
The most effective way to free up space is not deleting system files, but clearing the messenger cache and transferring media content to the cloud.
Frequently asked questions (FAQ)
Why is the amount of available memory less than stated in the specifications?
This happens for two reasons. Firstly, part of the space is taken up by Android system files and the manufacturer's shell. Secondly, manufacturers count gigabytes as 1000 bytes in a kilobyte, but the Android system counts them as 1024 bytes. This mathematical difference “eats up” about 7% of the declared volume.
Is it possible to increase the internal memory without a microSD card?
It is impossible to physically increase the memory chip inside the phone. Software methods that offer to “increase memory” through root access usually create a swap file on the existing media, which does not provide a real increase in volume, but only emulates working with memory, often slowing down the device.
Is it safe to transfer applications to a memory card?
It is safe for data, but can negatively affect the speed of applications. Memory cards, especially inexpensive ones, are slower than the built-in storage. If an application requires high data reading speed (for example, a heavy 3D game), it may become unstable when placed on an external card.
What is a .nomedia file and why do you need it?
File .nomedia is a hidden system marker. If you place it in your photos or music folder, the Android gallery and music player will ignore the contents of that folder. This is useful for hiding service pictures from instant messengers or album covers from the general music list.
How to find out your memory type (eMMC or UFS)?
This information cannot be found out with standard phone settings. You need to install a specialized application, for example Device Info HW or AIDA64. The “Storage” section will indicate the exact controller type and read/write speed of your drive.