Abstract: An improved garbage collection (“GC”) process configured to recover new blocks from used storage space is disclosed. After initiating the GC process for a flash memory in accordance with at least one of predefined triggering events, a first valid page within a first block marked as an erasable block is identified. Upon determining a first signature representing the content of the first valid page according to a predefined signature generator, the process identifies a second valid page within a second block as a duplicated page of the first valid page in response to the first signature. The process subsequently associates the logical block address (“LBA”) of the first valid page to the second valid page. In an alternative embodiment, page compression and sequential order of page arrangement can also be implemented to further enhance efficiency of garbage collection.