HomeFiction #2: Enterprise SSDs require DRAM or mixed SLC/MLC
Fact #2: SandForce enables MLC Enterprise SSDs without DRAM cache
Given that flash memory only sustains a limited number of P/E cycles and the enterprise workload will consume all available blocks in a short period of time, SSD manufacturers will often use other strategies to extend the life of the flash memory. A common approach to this problem is to add DRAM cache to the SSD to consolidate writes before they are written to flash memory in an attempt to lower the write amplification of the drive. This also adds cost and also increases the number of points of failure. Another path is to mix MLC with SLC on the same drive and send “hot data” (changes more often) to the higher endurance SLC and send “cold data” (changes less often) to the MLC. This helps reduce the number of writes to the MLC memory, but adds significant cost for the SLC memory and increases the complexity of the design.
When using SandForce SSD Processor with DuraClass technology in an SSD, none of these approaches are required to obtain a 5-year life from the drive. This keeps the complexity and costs down without compromise to life or performance.
