The Xiaomi 15 supports Storage refresh. Internal storage suffers from fragmentation, which will significantly slow down your phone. Storage refresh works automatically while you aren’t using the phone. It physically organizes your files into the smallest number of fragments reducing the lag.
With this feature, by organizing unused files, cache, and temporary data, Storage refresh helps free up space, creating faster device performance. Your phone can run smoother since it has fewer redundant files to process. When storage is optimized and free from unnecessary background processes, the device uses fewer resources, potentially extending battery life.
You can go to [Settings] >> [About phone] >> [Storage] >> swipe down to find and tap [Storage refresh] to check the refresh records.