A device’s IO performance describes its ability to write data In to and read data Out of the storage. Good IO performance is key to a smooth, stutter-free experience. The PCMark for Android Storage 2.0 benchmark is an isolating component benchmark for measuring the file IO and SQLite performance of the Android storage subsystem.
Storage 2.0 scores are not comparable with results from the Storage 1.0 test.
PCMark for Android measures storage IO performance in three areas.
Internal Storage is where your apps save private data such as settings and user data. The Android default cache directory is also in the internal storage. Files saved in internal storage are private to the application and cannot be accessed by the user or other applications. Internal storage performance most commonly impacts the start-up time and smooth running of your apps.
External Storage is used to save public data such as documents, photos, videos, and other files, as well as non-sensitive app data such as textures and sounds. Depending on the device, external storage can be removable, (such as an SD card), or built-in. Files in external storage can be found and modified by the user. External Storage performance most commonly impacts your experience when loading and viewing media files such as photos and videos.
The Database test measures performance when reading, updating, inserting and deleting database records using SQLite, the default relational database management system in Android. Following default Android behavior, the test database is saved in the device's internal storage.