Unleash the Potentials of Solid-State Drives via Sub-Page-Aware Sub-Block Garbage Collection

Solid-state drives (SSDs) have become the main-stream storage medium for modern consumer electronics, in-cluding both smartphone and mobile devices, with superior performance and reliability compared to traditional hard disk drives (HDDs). Despite their advantages, the full potential of SSD remains untapped due to the inherent constraint of the underlying NAND flash memory. These constraints call for the need for the flash translation layer (FTL) as the internal management of SSD to work with the constraints of NAND flash memory. With the technology advanced, innovative sub-page and sub-block architectures have been proposed to lessen the constraints and allow flexibility for optimization. Nonetheless, most of the previous FTL designs are either based on the sub-block or the sub-page architectures. The design issues of coexisting sub-page and sub-block within a single FTL receive much less attention. Such an observation motivates us to explore the possibilities of enhancing the SSD performance and lifetime through innovative sub-page and sub-block architectures. With the awareness of both sub-block and sub-page, this paper proposes methodologies to optimize read/write operations and increase the endurance of SSD to fit the storage demands of consumer electronics. This study presents a comprehensive analysis of the existing SSD architecture, identifies bottlenecks, and introduces novel approaches to overcome these challenges. Experimental results have been included to demonstrate the effectiveness of the proposed strategy.