The A1 symbol on Micro-SD cards tell you if it is fast enough for apps
With the introduction of the new SD card specification 5.1, the SD Association also announced new performance classes that are supposed to tell customers if a card is fast enough to run apps. So far only one level has been introduced, the A1 class. For a card to reach that level, it has to meet or exceed the following minimum requirements:
- Random Read Input-Output access Per Second (IOPS) of 1500
- Write IOPS of 500
- Sustained Sequential performance of 10MB/s.
Not only Android Smartphones can take advantage of Micro-SD cards for starting and running apps. The tiny cards are also popular in Windows tablets, convertibles and notebooks to expand onboard storage. Future SD cards carrying the A1 symbol will easily be recognized as being fast enough for that task. That, however, does not mean that current cards without that symbol are not able to meet or exceed the above mentioned minimum requirements.