Taking a look at microSD cards, you find different variables on there that some consumers might not have the slightest idea of what they represent. Today, we are going to cover one of these by taking a look at one variable that some readers have asked about in the past. The A1 or A2 that is printed on the face of the card.
You likely know what the size rating is when it describes the number as being so many MB or GB in capacity. But the A1/A2 rating isn’t so self-explanatory. Mostly because the average consumer doesn’t need to know. They just want something that works when it comes to storing information. However, if you are looking for specific performance and for certain devices, it helps to know what these other variables represent.
In this case, the A1 or A2 number represents the Application Performance Class of the card. This relates to the card being rated to work with the Android mobile operating system and the ability to store active apps on it vs the internal storage of a device. As you may know, Android devices allow you to install, store and run apps from external storage (the SD card) allowing you to expand upon the internal storage of the device. So it would benefit you to know that you are getting the right card if it will be used with your Android mobile device (smartphone, tablet, etc).
The rating represents the minimum specifications for IOPS (Input/Output operations Per Second). This highly affects the performance of apps and games as they are trying to run, due to all of the supporting graphics and other files bring manipulated on the backend.

So if you are shopping for a new microSD for your mobile device, it would benefit you to look for an A2 class card. Most devices will perform better with this since the minimum specifications for IOPS go from 1500(read)/500(write) to 4000(read)/2000(write).
It can easily be visualized as speed and multi-tasking for applications within your Android atmosphere. Where some variables on microSD cards refer to single actions like video encoding/writing, this one is all about multi-tasking within an operating system environment.
So it does matter which microSD card you pull from the shelf to buy, and it depends on what you are using that card for. Not every card has this printed on the front, so it is important that you look for it. A modern card that has quick read/write speeds and works great for 4K, doesn’t always mean it is the best for your Android device as well. So if you are buying a microSD card for such a device, make sure it has the A2 variable printed on the front to be sure. An educated shopper is a happy shopper (or at least your device will be happier).