Trade-off of performance, reliability and cost of SCM/NAND flash hybrid SSD

Storage-Class Memory (SCM), NAND flash hybrid Solid-State Drive (SSD) shows advantages of high performance and low power consumption compared with NAND flash only SSD. In this paper, first, three types of SCMs are analyzed respectively, with 0.1 μs, 1 μs and 10 μs read/write times. Then, their SCM/NAND flash capacity ratios are calculated to achieve the required SSD performance for the application. Next, by using these three types of SCMs, the acceptable SCM and NAND flash Bit Error Rates (BERs) are analyzed, which are limited by keeping specified SSD performance with error correction. Moreover, the acceptable BERs are also analyzed by considering the limitation of parity overhead size and SSD cost. At last, based on prior analyses, the acceptable BERs are summarized by considering the limitations of both SSD performance and cost.