Many flagship phones in 2015 (e.g., Galaxy S6, Galaxy Note 5, Moto X Pure edition) and in 2016 (e.g., Galaxy S7, and LG G5) all start with 32GB internal storage, but there are many middle range and budget Android phones may still only offer 16GB 0r 8GB or even 4GB storage.
Even for 32GB internal storage, owners usually can only use about 25-26GB. It seems a lot for most owners. But for some owners who play heavy games, who save some videos for long trip, or who save everything on the phone, the storage can be too limited.
For 16GB or 8GB phones, most owners may encounter insufficient storage message. They have to clean the internal storage for new apps at least a few times a year.
For 4GB phones, SD card slot is always provided. Otherwise, the phone is useless.
In most cases, yes, UFS 2.0 is faster than most micro SD card.
And in Galaxy S7, Samsung added micro SD card support back.
Traditionally, Android apps can only be installed on the internal storage, not SD card. Only some app data can be moved to SD card. And the support is determined by the app developer.
So, most owners use the SD card to save photos and videos and their downloaded files in Android phones.
This makes 4GB or 8GB Android phones more or less useless because apps usually are getting larger and larger. And this gives owners poor experience (owners usually tend to compare a sub-$100 Android phones with $700 iPhone).
As Google is targeting Android for next billion smartphone users who are mainly living in developing countries, it is important to improve the user experience of budget Android phones.
This is one of the major reasons why Google took a U-turn to improve micro SD card support in Android Marshmallow 6.0.
Now, you can use micro SD card in Android Marshmallow as internal storage. You can install all games without calculating storage. Basically, 4GB or 8GB storage will not be an issue for you to try games and apps.
For high-end smartphones, if you concern about performance, you have the option to use micro SD card in Android Marshmallow as portable storage as in previous Android versions.
I believe this is one of the best decisions Google has made for Android: focusing on ALL users, not just wealthy users.
What are the two different options when using micro SD card in Android Marshmallow?
As mentioned, you can use micro SD card in Android Marshmallow with two options:
- Internal storage (aka adoptable storage in Android Marshmallow). You can use micro SD card in Android Marshmallow as internal storage to expand internal storage. You can save anything on the SD card. Please read this guide on how to use micro SD card as internal storage.
- Portable storage. You will use the micro SD card mainly to save your media files or backups. You cannot install apps to it. Most apps will not use it for their app data. Please read this guide on how to use micro SD card as internal storage.
You need to make the decision.
Of course, you can change your mind later. But that will require formatting the SD card again. It may take time.
So, now let’s compare the pros and cons of these two options when you use micro SD card in Android Marshmallow devices.
Pros and cons of using micro SD card in Android Marshmallow as internal storage
If you use micro SD card in Android Marshmallow as internal storage, you can get these benefits:
- Value for money for more internal storage. You can expand internal storage in an affordable way. Most vendors may charge you about $30-$50 to get a 16GB model if the base model is 8GB. In other words, you may pay $30-$50 just for the 8GB storage. But for less than $50, you can get 64-128GB high-speed micro SD card. Very often, most vendors/distributors just stock base mode and you may have no way to get phone with more storage locally. So, this can be a perfect solution for you.
- Unlimited usage. you can save everything on the card. You just use your phone without worrying about insufficient internal storage.
- Simple to use after one-time setup. It is not necessary for you to know where the files are physically saved; everything is in the phone.
- Security. All data in the SD card are always encrypted. Even you lose your phone, you will not worry about the embarrassing photos or videos unless the thief can unlock the phone. They cannot access the files on the SD card from any other devices.
Of course, you need know the disadvantages of using micro SD card in Android Marshmallow as internal storage:
- Formatting the micro SD card is required. The phone will ask you to format the SD card when you use it first time, or when you change it from portable storage. It can take a few mins or longer and you need backup files on it.
- Inflexible. The micro SD card is encrypted and only can be read by the phone on which you format it. If you want to use the SD card on other devices, you have to format it again. When you connect the phone to a PC, or check the storage on the phone, you will not see a separate folders for the SD card. It is “merged” with internal storage.
- Performance may be affected. The possible performance impact depends on 1). phone storage type, UFS or eMMC; and 2). your micro SD card quality/speed.
- Back up, back up and back up. After you reset the phone, NO device can read the SD card, including your own phone because the encryption key will be destroyed when resetting the phone. So, it is important to back up the phone before resetting.
So, before you choose to use micro SD card in Android Marshmallow as internal storage, you need consider whether this is what you want.
Pros and cons of using micro SD card in Android Marshmallow as portable storage
The advantages of using micro SD card in Android Marshmallow as portable storage include:
- Flexible. You can use the micro SD card to share data/files among all devices. You can pop the card into any other devices to use it immediately.
- Performance. The performance of the phone will not be affected.
- Simple. This is similar to what you can do with a micro SD card in previous Android devices.
However, you should also be aware of the disadvantages of using micro SD card in Android Marshmallow as portable storage:
- Security issues. Anyone holds your micro SD card access all data on it (just like your USB drive). Although you may encrypt the SD card, you will lose the flexibility to use the micro SD card on other devices. Also, performance may be affected if you encrypt the SD card.
- Restricted usage. You cannot use micro SD for your apps or app data. Some vendors may allow you to move some apps to SD card, but most apps may not support it. Even you can move the app, only part of the app will be moved, not all.
- You cannot expand the phone internal storage.
Now, you may have better idea whether you should use micro SD card in Android Marshmallow as portable storage or as internal storage.
As mentioned, you can switch back and forth later. But it can take some time to switch.
Which should I choose: internal storage or portable storage
There is no perfect solution.
But there is a solution for YOU. It all depends on your personal situation.
You may consider to use micro SD card in Android Marshmallow as internal storage if:
- your phone internal storage is not more than 8GB.
- your phone internal storage is 16GB and you play some large games.
- your phone internal storage is 32GB and you play a lot of large games.
You may consider to use micro SD card in Android Marshmallow as portable storage if:
- your phone internal storage is 16GB or more and you seldom play large games. You can also easily backup photos and videos to Google photos easily.
- your phone internal storage is 16GB or more and you mainly use the phone to consume offline videos/music.
- your phone internal storage is 64GB or more.
Of course, this is just a rough guideline if you are a new Android phone user. If you have used Android phones for a while, you probably have a rough idea how much internal storage you need.
The bottom line is:
- if you need expand internal storage, use micro SD card in Android Marshmallow as internal storage.
- if you only need storage for your media files, use micro SD card in Android Marshmallow as portable storage.
Why I do not have the option to use micro SD card as internal storage in Android Marshmallow devices?
Some vendors may disable the option to use micro SD card in Android Marshmallow as internal storage for their own considerations.
At the time of writing this, this option is disabled in Samsung Galaxy S7, Galaxy S7 edge and LG G5.
Which micro SD card should I get for my device?
There are so many options when buying your micro SD card. You need consider 3 factors:
- micro SD card type supported by your phone.
- the capacity you need.
- your budget.
A lot of owners, and even some sellers, confused micro SD card types with speed class ratings.
For smartphones, there are 3 types of micro SD card based on capacity:
- standard-capacity micro SD (micro SCSD, or micro SD). The capacity of micro SCSD card is from 128MB to 2GB. It is normally formatted in FAT16.
- high-capacity micro SD (micro SDHC). The capacity of micro SDHC card is from 2GB to 32GB. It is normally formatted in FAT32.
- extended capacity micro SD (micro SDXC). The capacity of microXDHC card is from 32GB to 2TB. It is normally formatted in exFAT32 by default.
Most smartphones released in last 3 years support micro SDHC or micro SDXC (if they have a micro SD card slot). This means the phone either have a micro SDHC slot or microSDXC slot.
If the phone has a SDXC slot, you can use any micro SD card because the slot is backward compatible. If a phone says it supports more than 32GB SD card (e.g., up to 64GB, or up to 128GB or up to 200GB..), it means you can use any micro SD card.
If the phone has a SDHC slot, you can only use micro SDHC or micro SCSD cards. Micro SDXC card will not be recognized by the phone. If a phone says it supports SD card up to 32GB, it usually (not always) means it has a micro SDHC slot. But some may actually have a micro SDXC slot. In this case, you need check the specs of the phone to decide whether you can use a micro SDXC card.
Another parameter of SD card is the speed class rating. Please note, you only need get the correct micro SD type for your phone. The speed rating tells you how fast the SD card can write data.
Currently, there are 6 speed class ratings:
- Normal speed Class 2. The minimal writing speed is 2MB/s.
- Normal speed Class 4. The minimal writing speed is 4MB/s
- Normal speed Class 6. The minimal writing speed is 6 MB/s
- High speed Class 10. The minimal writing speed is 10MB/s.
- Ultra High Speed Phase I (UHS -I). The minimal writing speed is 10MB/s. The maximum writing speed can be up to 104MB/s. For example, this one.
- Ultra High Speed Phase II (UHS -II). The minimal writing speed is 30MB/s. The maximum writing speed can be up to 312MB/s. For example, this one.
The standard only specify the minimum writing speed. So, in the same speed class, the speed may vary sharply.
The rule of thumb for buying a micro SD card for your smartphone:
- get the correct micro SD card type.
- get at least Class 10 micro SD card.
- get a branded micro SD card if available.
- the best value ($/GB) of micro SD card currently is 32GB for micro SDHC and 64GB for micro SDXC.
- don’t overspend on capacity. Micro SD card are getting cheaper and cheaper (for per GB).
Do you have any question on how to use micro SD card in Android Marshmallow?
If you have any questions or problems on how to use micro SD card in Android Marshmallow, or have problems with SD card in Android Marshmallow, please let us know in the commenct box below.
The community will help you.
For any questions or problems with Android Marshmallow, please check our Android Marshmallow Guide page.
If your question is about Android Lollipop, please check out Android Lollipop Guide page.