NAND Flash Memory-Based SSD Controller Using Full Page-Associative Block Recycling Mechanism

A 36GB SSD controller enabling write endurance of 2 PB and 32K internal IOPS under random 4 KB page write workload is presented that offers 10 years of lifetime for random writes of 600GB/day. We point out that minimizing unnecessary data relocation is the single fundamental solution to maximizing effective write endurance and effective write performance. We propose a novel full page-associative block recycling mechanism combined with a feature for retrieving blocks that have the least amount of valid pages. A logically partitioned structure enhances the mechanism further by exploiting spatial locality.