The internal memory of a smartphone Android is its “digital brain”, where the operating system, applications, photos, videos and other data are stored. Without it, the device simply cannot work. But what exactly is hidden behind this term? Why do some phones run out of memory faster than others, even if they have the same capacity? And why do manufacturers often indicate “128 GB” in the characteristics, but much less is actually available to the user?
This article will help you understand how the internal memory of Androiddevices is structured, how they differ between eMMC and UFS, how to properly check free space and what to do if the memory runs out. We'll also touch on myths about "memory cleaning" and explain why some tips can harm your smartphone.
If you've ever encountered a "Not enough memory" notification or noticed that your phone starts to slow down after the storage is full, this information will be especially useful. Let's look at everything in order - from theory to practice.
What is Android internal memory and how does it work
Internal memory (or built-in storage) is a permanent storage device integrated into the motherboard of a smartphone. Unlike random access memory (RAM), which is cleared when the phone is turned off, the internal memory saves data even without power. The following are stored here:
🔹 System files - kernel Android, firmware, drivers and pre-installed applications.
🔹 User data - photos, videos, music, documents, downloads.
🔹 Installed applications — .apkfiles and their cache.
🔹 Settings and configuration —account data, network settings, interface personalization.
Physically, the internal memory is a microcircuit sealed on the board. Modern smartphones use two types of storage devices: eMMC (Embedded MultiMediaCard) and UFS (Universal Flash Storage). They differ in read/write speed, reliability and power consumption. For example, UFS 3.1 in flagships Samsung Galaxy S23 works 2-3 times faster than eMMC 5.1 in budget models.
It is important to understand that part of the internal memory is always occupied by the system. For example, on a smartphone with “128 GB,” about 100–110 GB is actually available to the user—the rest is taken up by the firmware, recovery partition, and service files. This is normal and is not a deception of the manufacturer.
Types of internal memory: eMMC vs UFS - which is better?
Not only the speed of the smartphone, but also its durability depends on the type of drive used. Let's compare two main standards:
| Characteristics | eMMC | UFS |
|---|---|---|
| Read speed | up to 400 MB/s (eMMC 5.1) | up to 2100 MB/s (UFS 3.1) |
| Write speed | up to 150 MB/s | up to 1200 MB/s |
| Power consumption | Higher | Lower (optimized) |
| Price | Cheaper | More expensive |
| Where used | Budget smartphones (Redmi, Galaxy A-series) | Flagships (iPhone, Galaxy S/Ultra, Pixel) |
🔹 eMMC is an outdated technology, but is still found in devices up to 20,000 ₽. Its main disadvantage is the low speed of random recording (for example, when installing applications or updating the system). This can lead to “freezes” of the interface.
🔹 UFS is a modern standard that uses the protocol SCSI (as in SSD for PCs). It supports full duplex mode (simultaneous reading and writing), which speeds up multitasking. For example, in OnePlus 11 applications open almost immediately. instantly. UFS 4.0 Applications open almost instantly.
⚠️ Attention: If your smartphone on eMMC begins to slow down a lot after the memory is filled to 80%+, this may be a sign of cell wear. In such cases, only replacing the board or resetting to factory settings helps.
Interesting fact: some manufacturers. (for example, Xiaomi) in budget models they combine eMMC with a small volume UFS to cache frequently used data. This is called TurboWrite and gives a speed increase of up to 30%.
Why is UFS more expensive. eMMC?
Producing UFS requires more advanced technological processes (for example, 3D NAND memory) and additional controllers to control the speed. In addition, licensing the UFS standard is more expensive for manufacturers than eMMC.
How to check the amount and status of internal memory
To learn how much memory is occupied and free, you do not need third-party applications - built-in tools are enough Android. Here's how to do it:
1. Open Settings → Storage.
2. At the top of the screen you will see a diagram with memory distribution by categories:
- System (firmware and pre-installed applications),
- Applications,
- Media files (photos, videos, music),
- Cache,
- Other data (downloads, documents).
3. Click on any category to see details. For example, in the “Applications” section you can sort apps by size and delete unnecessary ones.
🔹 Useful life hack: Some firmware (for example, MIUI or One UI) have a “Memory Cleaning” function that analyzes unnecessary files (duplicate photos, old APKs, messenger cache). It is located in the same section Storage.
⚠️ Attention: If in the “Storage” section you see the “Other” category with a volume of several gigabytes, it could be:
- Residual files after uninstalling applications,
- System logs (for example, /data/log),
- Hidden folders of some games (for example, Genshin Impact or Call of Duty Mobile).
They can be deleted manually through a file manager (for example Files by Google) or special utilities like SD Maid.
For advanced users: to see the complete memory structure, connect the phone to the PC and use the ADBcommand:
adb shell df -hIt will show all partitions (/data, /system, /cache) and their fullness.
Delete application cache in Settings → Storage
Transfer photos/videos to the cloud (Google Photos, Yandex Drive)
Delete unused applications (especially games)
Empty the Downloads folder of old files
Use the "Storage Optimization" function (if available)-->
Why does internal memory run out so quickly?
Many users are faced with the fact that even on a smartphone with 128 GB of memory, the free space is melting away before our eyes. Here are the main reasons:
🔸 Application cache —temporary files that are created to speed up the operation of apps. For example, Instagram or TikTok can accumulate 1–2 GB of cache per month.
🔸 Application updates —new versions take up more space. For example, Facebook after an update it can “swell” from 150 MB to 500 MB.
🔸 Hidden messenger files — Telegram and WhatsApp by default save all media files to the phone memory. With active use, this is hundreds of megabytes per day.
🔸 System dumps and logs — in case of failures Android creates debug files (/data/tombstones), which can take up to 1–2 GB.
🔸 Memory fragmentation —over time, files are “scattered” across different sectors, which reduces the efficiency of space use (especially on eMMC).
🔹 An example from life: The user installs the game Genshin Impact (about 15 GB), plays for a month, then deletes it. But up to 2-3 GB of “tails” remain in the memory - saves, cache and temporary files.
⚠️ Attention: Some "memory cleaners" (for example, Clean Master or CCleaner) promise to free gigabytes, but in fact they delete useful files or simply clear the cache, which will be restored in a few hours!
To really save space, it is better to do it manually:
- Disable auto-loading of media in instant messengers,
- Remove unnecessary language packs in games (for example, in Settings → Language and input → Application languages),
- Transfer heavy files on SD card (if supported).
Google Photos has a “Free up space” function - it deletes photos and videos from your phone that are already uploaded to the cloud, but leaves thumbnails. This is safe and frees up gigabytes!
How to increase internal memory. Android
If memory is sorely lacking, there are several ways to expand it:
📌 Use an SD card as internal memory (Adoptable Storage):
- Powered by Android 6.0+,
- The card is formatted and encrypted, after which it becomes part of the main storage
- Minus: not all applications support transfer to SD.
📌 Connect an external SSD via OTG:
- Modern smartphones support USB-C SSD (for example, Samsung T7),
- Read/write speed is higher than that of SD cards,
- Suitable for storing a media library or backups.
📌 Optimize existing memory:
- Remove duplicate photos (applications Duplicate Files Fixer),
- Compress videos without losing quality (Video Compress),
- Transfer applications to the memory card (if supported).
🔹 Important: Function Adoptable Storage (turning an SD card into internal memory) has limitations:
- The card must be fast (class UHS-I U3 or higher),
- After formatting, it cannot be used in other devices.
- On some firmware (MIUI, EMUI) this function is disabled by the manufacturer.
⚠️ Attention: If you use SD card as internal memory, its wear will increase by 2-3 times due to frequent rewriting. It is recommended to use cards with a high resource (SanDisk Extreme Pro, Samsung PRO Endurance).
| Method | Pros | Cons |
|---|---|---|
| Adoptable Storage (SD as internal memory) | Cheap solution, does not require root | Not all applications support, the card wears out faster |
| External SSD via OTG | High speed, large volume | Expensive, you need to carry it with you |
| Cleaning and optimization | Free, does not require equipment | The effect is temporary, needs to be repeated |
The most reliable way to “increase” memory - regularly clean it of unnecessary files and use cloud storage for backups.
What to do if the internal memory is damaged?
If your smartphone starts to show errors like “Memory is damaged”, “Cannot write files” or “SD card is unrecognized”, this may indicate hardware or software problems:
🛠 Software glitches:
- Reboot the phone - sometimes this solves temporary file system errors.
- Check the memory for errors via ADB:
adb shell fsck /dev/block/mmcblk0(root access required).
- Reset the settings to factory settings (Settings → System → Reset), but first make a backup!
🛠 Hardware problems:
- If the phone was dropped or wet, the memory contacts could oxidize.
- On eMMC-drives, the cells wear out over time (especially if the memory is 90%+ full).
- In rare cases, the memory controller is to blame - only repair will help.
⚠️ Attention: If, when connected to a PC, the smartphone is detected as a “removable disk” with a request to format it - don't agree! This will lead to complete loss of data. Instead, try:
1. Remove the memory card (if any) and reboot the phone.
2. Connect to another USB port or cable.
3. Use recovery apps (DiskDigger, Recuva) to save files.
🔹 Symptoms of “dying” memory:
- The phone spontaneously reboots when writing files,
- Photos/videos are saved with artifacts,
- The operating speed drops even after resetting the settings.
In such cases, the only solution is to replace the memory chip at a service center. The cost of repair depends on the model:
- Budget smartphones (Redmi, Galaxy A): 3 000–6 000 ₽,
- Flagships (iPhone, Galaxy S): 8 000–15 000 ₽.
Is it possible to recover data from damaged memory?
Partly yes, but success depends on the type of damage. If these are logical errors (for example, after incorrectly removing the SD card), apps like TestDisk or PhotoRechelp. In case of physical damage (oxidation, burnt controller), the chances are minimal - you will need professional equipment (for example, PC-3000 Flash).
Myths and truths about Android internal memory
Around internal memory There are many myths. Let's look at the most popular ones:
❌ Myth 1: "Formatting the memory speeds up the smartphone."
✅ True: Format simply clears the data, but does not affect the speed. eMMC/UFSIf the phone is slow, the problem may be fragmentation. (on eMMC) or cell wear.
❌ Myth 2: "Closing background applications saves memory."
✅ True: Android automatically manages memory. Forcibly closing applications can, on the contrary, increase the load, since the system will have to download them again.
❌ Myth 3: "A class A1/A2 SD card speeds up the phone."
✅ True: Class A1/A2 is only important if the card is used as internal memory (Adoptable Storage). For regular storage of photos/videos, a class is sufficient UHS-I U3.
❌ Myth 4: "Clearing the cache is harmful."
✅ Truth: The cache can be cleared, but it is temporary measure. For example, clearing the cache Google Play Services may result in data being downloaded again the next time you launch applications.
❌ Myth 5: "Internal memory cannot be filled more than 80%."
✅ Truth: This is relevant for HDD and old eMMC, but not for UFS. Modern drives are optimized to operate at up to 95% capacity. However, at eMMC 4.5/5.0 at 90%+ fill the speed may drop.
🔹 Advice from an expert: If you often shoot video in 4K or play heavy games, choose a smartphone with UFS 3.0+ and a reserve memory. For example, Genshin Impact with high quality textures you need at least 20 GB of free space.
FAQ: Frequently asked questions about Android internal memory
Can I move applications to an SD card without root?
Yes, but not all applications support this feature. You can use Android 6.0+ can be used Adoptable Storage (SD as internal memory), but this formats the card. An alternative is to manually transfer supported applications to Settings → Applications → [Select application] → Storage → Edit → SD card.
Why is there less free memory after an Android update?
Firmware updates often take 1-3 GB and can create backup copies of old files (for example, a folder /cache/ota). The system can also reserve space for future updates. To free up space, clear the update cache in Settings → Storage → System data.
How do I find out what type of memory (eMMC or UFS) is in my smartphone?
Officially, manufacturers rarely indicate this parameter. You can:
1. View tests in AnTuTu Benchmark or AIDA64 —the drive type is displayed there.
2. Look for disassembly of your model on YouTube or iFixit —the chip markings are usually visible there.
3. Check the model on sites like GSMArena or NotebookCheck (the memory type is sometimes indicated there).
What will happen if the internal memory is 100% full?
The smartphone will start to work unstable:
- Applications will crash,
- It will not be possible to install updates or new apps,
- The camera may refuse to save photos/videos,
- The system will freeze when recording data.
On eMMC this will also speed up the wear of the cells. It is recommended to leave at least 5–10% of free space.
Is it possible to replace the internal memory in a smartphone?
Theoretically yes, but in practice it is:
- Very expensive (the cost of the chip + work can exceed the price of the phone),
- Not always possible (in some models the memory is sealed into the processor, as in Apple A-series),
- Requires specialized equipment (soldering station, microscope).
In 99% of cases it is cheaper to buy a new phone or use external drives.