BACKGROUND

In order to save cost, a storage system can store data in multi-level cell (MLC) (e.g., triple-level cell (TLC) or quad-level cell (QLC)) blocks in its memory instead of single-level cell (SLC) blocks. However, SLC blocks typically have a faster write speed. To improve write performance, some storage systems use SLC blocks as a write buffer, where data is initially stored in the write buffer and later flushed to MLC blocks in the memory. For example, the WriteBooster™ feature in the Universal Flash Storage (UFS) standard creates an SLC cache in flash memory that can be used to improve write speed.

