Introducing vSphere 6.7 for Enterprise Applications
vSphere 6.7 introduces new storage and networking features which have a major impact on the performance of Enterprise Applications – these include support for Persistent Memory (PMEM) and enhanced support for Remote Directory Memory Access (RDMA).
Persistent Memory (PMEM)
With vSphere Persistent Memory (PMEM) , customers using supported hardware servers, can get the benefits of ultra-high-speed storage at a price point closer to DRAM-like speeds at flash-like prices.
The following diagram shows the convergence of memory and storage.
Technology at the top of the pyramid (comprised of DRAM and the CPU cache and registers) have the shortest latency (best performance) but this comes at a higher cost relative to the items at the bottom of the pyramid. All of these components are accessed directly by the application – also known as load/storage access.
Technology at the bottom of the pyramid – represented by Magnetic media (HDDs and tape) and NAND flash (represented by SSDs and PCIe Workload Accelerators) have longer latency and lower costs relative to the technology at the top of the pyramid. These technology components have block access meaning data is typically communicated in blocks of data and the applications are not accessed directly.
PMEM is a new layer called Non-Volatile Memory (NVM) and sits between NAND flash and DRAM, providing faster performance relative to NAND flash but also providing the non-volatility not typically found in traditional memory offerings. This technology layer provides the performance of memory with the persistence of traditional storage.
More details about this can be found here.