Dell EMC PowerVault MD 34XX/38XX Series Storage Arrays Administrator's Guide

The SSD cache feature uses solid-state disk (SSD) physical disks to improve read-only performance in your storage array. SSD physical disks are logically grouped together to provide secondary cache for use with the primary cache in the RAID controller module memory.

Using SSD cache improves application throughput and response times and delivers sustained performance improvement across diverse workloads, especially high-IOP workloads.