Pure Storage, a company specializing in All-Flash storage systems, believes that further increases in SSD capacity will be fraught with a number of difficulties dictated by the need to use DRAM. Shawn Rosemarin, Pure's vice president of research and development, told Blocks & Files. According to him, commercial SSDs require approximately 1 GB of DRAM for every 1 TB of flash memory. DRAM is required for the Flash Translation Layer (FTL) subsystem. According to Rosemary, a 30 TB drive requires 30 GB of DRAM, a 75 TB drive requires 75 GB, etc. Thus, for an SSD with a capacity of, for example, 128 TB, you need 128 GB of DRAM, and this is already comparable to the amount of RAM in the server .
Source: 3dnews.ru