Software-defined memory

Software-defined memory (SDM) is the new convergence of storage and memory, which previously were two separate computing domains. Storage is a multi-layer software implementation outside of the realm of Computer Architecture (i.e. I/O subsystem).

History

SDM was coined in 2014 by SanDisk for the software which leveraged their SSD and persistent memory devices. Both devices located on the processor's peripheral I/O subsystem, i.e. on PCIe-based cards.

The following year (2015) was a crucial year for the standardization of plug-and-play DDR4-based NVDIMM cards. These persistent memory devices reside on the processor's memory subsystem, which requires broader platform support, but is a better fit, because it was designed for memory-like latencies and cache-line granular access. 2015 also saw several key announcements of new storage-class memory (SCM) based devices, such as Intel & Micron 3D XPoint, HPE & SanDisk memristors, Samsung & Netlist NVDIMM-P and Sony & Viking Technology.

Description

SDM is a software solution that can utilize standard heterogeneous off-the-shelf persistent memory devices and present them using standard APIs in a way that hides the internal complexity. It may support multi tiers (e.g. NVDIMM, SSD and HDD) in order to allow flexible price points, as well as other data services.

See also

• Storage virtualization
• Memory virtualization