Soon you will know if your new microSD card can run apps well on your phone

Internal storage on a smartphone or tablet can quickly be used up by lots of apps, which is why having an microSD card slot for those devices is becoming more important. This week, the group that handles specifications for those cards, the SD Association, announced the Application Performance Class, which is designed to label SD and microSD cards that over solid performance for mobile apps.

• Best phones with expandable memory
• Best microSD cards

Since the launch of Android 6.0 Marshmallow in 2015, Android devices could use the Adoptable Storage feature, allowing microSD cards to be added to a phone’s amount of internal storage, rather than as a separate storage item. This week’s launch of the Application Performance Class specification, which is part of the overall SD Specification 5.1, is supposed to give consumers a heads-up on which of those cards are best suited for running apps. Those cards will likely be solid performers in Adoptable Storage situations.

Cards with the “A1” symbol, as shown above, have been approved for the first level of the new Application Performance Class specification. If you see that symbol on a microSD card, that means it can meet or exceed certain standards, such as Random Read Input-Output (IOPS) of 1,500 per second, Write IOPS of 500 per second, and Sustained Sequential performance of 10MB per second.

In addition to the new A1 label on microSD cards, the symbol could also be shown on new smartphones and tablets, to make sure consumers know that their device and their card can run apps with a high enough degree of performance.