With the expanded usage of SD memory cards for storing applications and application data, there is a growing need for a combination of random and sequential performance levels.  This demand becomes even stronger with the introduction of Android’s Adopted Storage Device capability.

The App Performance Classes assure minimum random and sequential performance speeds to meet both run and store execution time requirements under given conditions, while still providing storage of pictures, videos, music, documents and other data.

This table describes the Application Performance Class 1 (A1) and Class 2 (A2) specification and the minimum random read performance inputs/outputs per second (IOPS), minimum random write performance(IOPS) and the minimum sustained sequential performance (MB/s) of the corresponding SDHC/SDXC Memory Cards under the conditions defined in SD 5.1/SD 6.0 Part 1 Physical specification.

You can read more details about the Application Performance Class in our
white paper