Radian’s award winning Zoned Namespaces (ZNS) implementation simplifies integration while providing optimized performance



Case Study

In-depth case study of IBM Research’s integration of Radian’s Zoned Flash SSD with their SoftwAre Log Structured Array (SALSA) storage stack
including integration analysis, quantifying development times, and their performance results






Cooperative Flash Management configurations for either Zoned Namespaces (ZNS),
the original Symphonic API, or an Open-Channel 2 compliant interface

U.2 form factor with Dual Port or Single Port configurations

Up to 12GB PMR style User NV-RAM

Up to 16TB Flash



Software-Defined Flash:
the answer to the SSD Delta

Why can’t conventional SSDs deliver the capacity, performance,
or endurance of their own raw Flash?

FTLs and the SSD Delta

Utilizing NAND memory for data storage requires performing Flash management processes, such as garbage collection and wear leveling.

SSDs perform these processes transparently in a black box known as the Flash-Translation-Layer (FTL) that abstracts the processes and emulates hard drives for backwards compatibility.  But this abstraction significantly reduces the native performance and cost metrics available from the raw NAND memory, creating a gap that we call the SSD Delta.

Challenges from SDF

  • Difficult integration and significant modifications to target host software stacks
  • Burdens host with low level NAND details
  • Lacks Forward Compatibility and ties host software to geometry and vendor-specific NAND properties
  • Lacks Reliability, Availability, and Serviceability features
  • Poor scalability as SSDs are added to a system


As a subset of SDF, Radian’s Symphonic technology preserves the SDF advantages while specifically addressing each of the resulting challenges to provide the functionality required of a data center class product.