CPDT is a performance benchmarking tool for Android devices. It measures the performance of internal and external storage devices. The benchmarking tool provides various measurements for hardware such as SD Card, NAND, UFS, USB Drive and for devices such as internal storage and RAM. 

The performance benchmarking tool works on Android devices with an API level of 11 or higher. The API level of the device is specified in the Settings application of your device. The tool works in its own built-in language called Android.

After starting, you can click on the Test option. This starts the test and shows you the results.