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 Application Performance Class was introduced by SD 5.1 specification with the first App Performance Class1 (A1), to address these new application-intensive market demands. The new A2, introduced in SD 6.0 specification, is the next class level and provides more flexibility in the market for cost-performance optimization per product or application need and various market segments. The newly introduced functions of Command Queuing, Cache, and Self-Maintenance are SD protocol functions that enable higher performance levels.
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. The App Performance symbol lets manufactures easily communicate device requirements and helps their customers choose the right card for their device at the point-of-sale. This innovation isn’t limited to just smartphones. Cards offering this new level of performance may fit any type of use that can benefit from improved random performance.
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. Watch our video about the Application Performance standard.