Our computerized world is replete with all kinds of gadgets and accessories for them. Therefore, not everyone knows what an SD card is, what it is needed for and how many varieties there are.
Memory card and its features
A memory card is a small and fairly thin plate with a built-in flash memory module, which is non-volatile. This means that the information on it is retained even when it is removed from the device. Information can be deleted and rewritten many times. The service life of a memory card is calculated in decades. On some of them, information can be protected using certain methods.
Types of memory cards
At the moment, you can find many different types of memory cards on the market. In this article we will focus on the most popular types.
SD (Secure Digital) is the most popular type of memory card. It is used in many cameras, old players, tablets, video cameras, pocket computers and communicators. It can be purchased at all computer stores and communication stores for a fairly low price. The maximum capacity of such a card is 4GB.
SDHC cards include all SD memory cards larger than 4GB. This type of card is faster. Their maximum capacity is 32GB. It is preferable to purchase SDHC cards, but keep in mind that some older devices do not work with them.
SDXC is a new standard that is not yet widely adopted. Such cards are distinguished by their enormous capacity, which can reach 2 terabytes, and extremely high data writing speed. Their price is quite high, and they are not found on sale very often. In addition, this format is still supported by few devices today.
MiniSD is similar to SD, but smaller in size. Now it is practically not used, since it has been replaced by the microSD format, so buying it is problematic and expensive.
MicroSD differs from SD in its small size, and they are cheaper. True, it has one drawback - it is easy to lose, but on the other hand, it is very convenient, as it fits into any connector on any device. Now you know what an SD memory card is and what types you can buy, and you are unlikely to be confused when choosing one.
Starting with version Android 6.0, it became possible to use a flash card as internal storage device data. Now the device, after certain actions, can use the memory available on the SD as freely as the internal one. The article will tell you how to connect an SD card in this quality and what restrictions are imposed on it.
How to connect a flash drive as internal memory
Before connecting the drive, you must transfer from it all important information. During the setup process, it will be completely cleared and the data will not be returned.
First of all, you need to go to Settings, and then go to the section " Storage and drive", where you should click on the SD card.
Next you need to select “ Tune" and click " Inner memory" Immediately after this, the device will warn the user that all information will be deleted and it will become impossible to read it on other devices without full formatting.
Here you need to select the item “ Clear and Format" and wait for the memory clearing process to complete. You may then receive a message indicating that the media is running slowly. As a rule, this means that the flash drive used is not of very good quality and its use as device storage may also affect the performance of the smartphone itself. For good and fast work recommended to use UHS Speed Class 3 (U3) drives. 
After formatting is completed, the smartphone will ask you to transfer information, you should agree with this and wait until the work is completed. After the transfer, the work of turning the flash drive into internal memory will be almost complete; all that remains is to reboot the device. 
Features and limitations of using an SD card
There are a few things you should be aware of before you start using a flash drive in this way.
- After conversion, all data, except for some applications and system updates, will be placed on the SD drive.
- When connected to a computer, only this part of the memory will be available for interaction.
In fact, all actions are performed only with a flash drive, the real internal storage of the phone not available for interaction and is practically not used at all. Firstly, this means that when you remove the drive, almost all your data, photos and applications will be lost. Secondly, if the volume of the flash drive is less than the actual storage capacity of the smartphone, then the amount of available memory will decrease, not increase.
Format the card using ADB for use as internal storage
The function is not available on some devices, but it is possible to connect a flash drive as storage in another way. However, it is worth noting that this method is very labor-intensive and can cause damage to the device Therefore, if you are not confident in your abilities, then it is better not to do this on your own.
To use this method, you will need to perform many steps. You need to download from the site and install Android SDK, then download and install from the official website device drivers, and also, you need to enable “ debug modeUSB» on the device.
- adb shell
- sm list-disks (after execution, an id will be issued in the form disk:ХХХ,ХХ should be written down and entered in the next line)
- sm partition disk:ХХХ,ХХ private
Then you will need turn off the phone, go to settings and click on sd, select menu and click “ Transfer data" That's it, the actions are finished.
How to set a memory card to standard mode
To return the flash drive to standard mode, you just need to go to its settings, as in the first option, and select “ Portable media" Before doing this, all important information should be transferred to another location, because the drive will be formatted during the process. 
Some Android devices have slots for memory cards (usually microSD format). If your device supports SD cards, you can:
- increase memory capacity;
- use the card for some functions and applications.
To find out if your device has an SD card slot, visit the manufacturer's website.
Note. Some of these steps can only be performed on devices running Android 6.0 and later.
How to install an SD card
Step 1: Insert the SD card.- Check where the SD card slot is located.
- Turn off your phone.
- Remove the SD card tray or remove the back cover of the device (depending on the model). If necessary, lift the tab that holds the card.
- Place the SD card in the slot. If you raised the retaining tab, lower it.
- Reinstall the SD card tray or back cover of the device.
- Wait for the SD card notification to appear.
- Click Tune.
- Select the desired storage type.
- Removable storage:
You can transfer the card to another device along with all your files (such as photos and music). Applications cannot be moved to a removable drive. - Inner memory:
The card can store apps and data only for that device. If you move it to another device, all data on it will be deleted.
- Removable storage:
- Follow the onscreen instructions to set up your SD card.
- When finished, click Ready.
How to use an SD card
How to move apps to SD cardIf you have connected the card as internal storage, you can transfer applications to it.
Note. Not all applications can be transferred to an SD card.
How to move files to SD cardIf you have installed an SD card as a removable storage device, you can transfer various files to it, such as music and photos. After that, they can be deleted from the device’s internal memory.
Step 1: Copy files to SD card.
Step 2: Delete files from your internal storage.
You can view the contents of the SD card and see how much space is left.
When the SD card is used as internal storage
When the SD card is used as a removable storage device
- Swipe down from the top of the screen to open the notification panel.
- Under the SD card notification, tap Open.
It would seem that there is nothing difficult about buying a memory card. We decided on the required volume, found a good deal and bought it. It is because of this approach of users that some manufacturers offer flagship smartphones with expandable memory. If you have a microSD card at hand, take a look at how much stuff is written on it. This information will help you make the right choice.
Why bother with all this?
This is the question to start with. Imagine that you bought a new modern flagship smartphone with memory card support, for example, LG G4. Such a smartphone should easily cope with all tasks, but suddenly you notice that the camera and other applications of your smartphone are not working as fast as you expected. This is possible if you are using a memory card that is not fast enough, on which photos are saved and from which your applications take data. However, nothing prevents you from paying a little attention to the issue and choosing the memory card with which your smartphone can please you constantly.
What is the difference between SDHC and microSDXC?
When buying a memory card, you should pay attention to these big four letters, but the difference between these two standards is only in the supported amount of data. SDHC (Secure Digital High Capacity) allows you to store up to 32 gigabytes of data, while SDXC (Secure Digital Extended Capacity) can handle 64 gigabytes and above. The problem is that not all devices support SDXC cards and such a large amount of memory. Check the capabilities of your smartphone before purchasing a 64 or 128 GB memory card.
What does the memory card class mean?
microSD cards can be grade 2, 4, 6, and 10, and this is what you really need to pay attention to. These numbers indicate the supported data transfer speed, and while a microSD memory card can write data at a minimum speed of 2 MB/s, a Class 10 memory card works at a minimum speed of 10 MB/s. Not that difficult. It is important to understand that we are talking about the minimum write speed, and with good memory cards the data read speed can reach up to 95 MB/s.
What does UHS mean?
Another information about the memory card that you may notice is UHS-1 or UHS-3 compatibility. Such microSD memory cards began to appear in 2009. In theory, a UHS card can support data transfer speeds of up to 321 MB/s, but you should focus on the minimum speed: 10 MB/s for UHS-1 and 30 MB/s for UHS-3. In fact, if you plan to use the card in a smartphone, you should not focus on this, smartphones do not support UHS.
What else is important to know?
It would be a good idea to purchase a memory card from one of the trusted manufacturers, for example, SanDisk, or Kingston. It is also worth paying attention to the cost. If you suddenly find a suspiciously cheap memory card, you should be wary of it.
Based on materials from AndroidPit
The amount of information required for work and entertainment is increasing every day. The quality of photographs and video files increases, and along with it their “weight” also increases. As a result, the built-in memory of our gadgets, especially those from the budget segment, is sorely lacking. This problem can be easily solved, especially in phones with a removable battery. Why in them, how to choose a memory card for a phone for any budget and many other issues will be discussed in this article.
Memory card. What is this?
Typically, the memory card is a small black rectangle, but sometimes the appearance is different. Depending on the model, it has a different amount of memory. Modern models of various gadgets use only one type of memory card - microSD, although there are quite a large number of them.
Previously, when mobile phones were just beginning to acquire additional memory, each manufacturer tried to invent its own format, different from the others. For example, the memory card of an LG phone could not be installed in a Nokia. Over time, this trend, as well as specific charging connectors, gradually faded away. This has its own advantage, because after changing your smartphone, you now don’t have to re-purchase this important accessory for it.
How much volume do I need?
When it comes to the required capacity of an SD Card, you should first ask yourself what files you work with most often. In order to get your bearings at least a little, you can take a look at the following list, showing the approximate size of the files we are used to:
- Melody or track - from 3 to 10 megabytes.
- Photo - from 1 to 5 megabytes.
- Film (depending on quality) from 700 megabytes to several gigabytes.
If you are used to using only high-quality content, then you will have to think about memory cards of 32 GB or more. If the card is needed only to store a small playlist and current photos, its volume can be easily calculated using the above information. We can definitely say that with large volumes of photos, there will not be enough internal space, and a memory card is required. A phone with 2 GB of memory is simply not capable of storing the number of videos and photos that modern youth are accustomed to taking.
Feature regarding the capacity of the new memory card
Probably everyone who has previously encountered memory cards or flash drives has noticed that there is a little less space on them than stated by the manufacturer. Why does this problem occur and can it be fixed?
In reality there is no problem. The reason lies in the principles of computing space by a computer or telephone. We are accustomed to multiplying all quantities by a thousand, as, for example, there are a thousand grams in one kilogram. However, in the computer world, calculations are done a little differently, and a number of 1024 is considered to be one. As a result, such an error arises on the missing 24 bytes for every thousand. Therefore, manufacturers should not be blamed for such a “shortage”, and an SD memory card with “cut down” memory is actually quite normal.
What is a memory card class
All memory cards are divided not only by capacity, but also by class. Therefore, when you decide how to choose a memory card for your phone, do not forget about this parameter. The class displays the speed at which any information is written to it. There are cards of various classes, but the most popular in our stores are 4, 10 and U1.
In fact, everything is clear with digital classes - a four is equal to a write speed of up to 4 MB/s, and a ten is equal to up to 10 MB/s, respectively. With the U1 class it is a little more interesting, since manufacturers promise speeds not up to, but from 10 MB/s, but what the maximum possible will be, you have to check on the spot. This class is considered a newer standard, and the SD memory card marked with it differs better from its predecessors.
In addition to the above, there are also digital classes SD Card 2 and 6, as well as the new generation class U3. Digital are no different from their predecessors, that is, they correspond in the same way to the maximum recording speed. Class U3 is currently considered the highest and allows you to write information at speeds of over 30 MB/s. But, despite the high level of development of smartphones, none of them need such a high speed yet, so we will not consider it in detail.
Which one do I need?
Let's look at what each class of memory card can be used for. This will be another step towards how to choose a memory card for your phone and not make a mistake.
- Class 2 memory cards are designed for data storage and are the slowest and cheapest option. You can record music and video files on them, but the recording process itself will be quite lengthy. Problems may occur when viewing high-definition videos.
- Class 4 memory cards are the most popular and common. Fully meet the speed needs of budget phones and smartphones related to multimedia files. Still, it’s better not to use it for games and programs.
- Class 6 memory cards can already be a replacement for the internal memory of some electronic devices and are designed for recording and storing any type of files.
- Class 10 memory cards are the fastest type of cards, the maximum capabilities of which can be used by any smartphone. Allows you to record video in high resolution and perform other tasks that require high-speed recording of information.
- U1 class memory cards are an improved class 10, with a slightly higher write speed and significantly faster reading, as a result of which they can be used for program files, since loading from them will be much faster.
- U3 class memory cards are used very rarely, since their characteristics are only needed when recording video in 4K resolution, and the cost is very high.
What is the maximum memory card capacity supported by the device?
Often, most manufacturers themselves indicate in the characteristics of a phone or smartphone what size memory card is recommended to be installed in the gadget. However, sometimes this information is not indicated directly, but using the coding of different types of cards. It's worth taking a look at the device specification and seeing which cards are supported. The following may be written there:
- microSD cards are an old standard that requires the installation of a phone micro memory card with a capacity of no more than 4 GB. Sometimes some Chinese manufacturers write that cards up to 8 GB are supported with the same marking, but no more.
- microSDHC cards are the most common format among budget phones and smartphones today. Provides the ability to expand memory with cards up to 32 GB, which is quite enough for most users.
- microSDXC cards are a new format that allows you to work with volumes up to 2 TB. Often, cards of this size can be very expensive, but a very popular, inexpensive, and functional solution would be to install additional memory of 64 or 128 GB.
How to decide on the manufacturer
In fact, there is not much difference between memory cards from different manufacturers. They are all quite reliable, so the final weighty argument when choosing can only be the price or attractive appearance. The speed of the card, as discussed above, depends only on its class.
Sometimes on older devices there is a situation where memory cards of the maximum capacity for the gadget do not work from all manufacturers. Even the developers of this or that gadget cannot answer what this is connected with. For example, a similar question was previously discussed on forums - I bought a regular memory card, I didn’t see it at close range, although it worked with other devices without problems. Therefore, when buying a memory card, it is best to take with you the device for which it is intended. This way you can avoid unnecessary stress associated with returning an incorrect accessory.
Instructions for installing a memory card
How exactly and where to place the card itself is often written in the user instructions for the device. However, another important point is often missed. Some devices can easily read data written to a card with a file system of one of the common formats. But after prolonged use, failures may occur, which can lead to the loss of important information.
To prevent this from happening, it is recommended that immediately after installation, while there is no data on the card, you format it directly using your phone or smartphone. Don’t be lazy to do this operation, because later it can protect you from unnecessary worries. This concludes the recommendations on how to choose a memory card for your phone. We hope you will not have any problems purchasing this accessory.