Application Driven SCM and NAND Flash Hybrid SSD Design for Data-Centric Computing System

In order to efficiently store, retrieve and process big data, the data-centric computing paradigm is adopted and an application-driven storage class memory (SCM)/NAND flash hybrid solid-state drive (SSD) is designed. SSD data management algorithms minimize data movement inside the storage system and the SSD system design parameter, SCM/NAND capacity ratio, is chosen depending on the application. Design guidelines are proposed, based on the evaluation of three SCM/NAND flash hybrid SSDs with: (1) write-back (WB) cache, (2) write-optimized data management (WO-DM) and (3) read-write balanced data management (RWB-DM) algorithms. The WO-DM algorithm achieves the highest SSD performance for write-intensive applications, whereas RWB-DM is most appropriate for read-hot (frequently accessed)-random workloads. As long as the workload is not read-cold-sequential or write-cold-sequential, adding SCM to the NAND SSD system is cost-effective to boost performance. Less than 10% SCM/NAND capacity ratios provides 10x speed, compared to the NAND flash-only SSD.