Case Study on the integration of SALSA, a unified storage software stack developed by IBM Research, with Radian’s Zoned Flash SSD

This case study provides an industry-first overview of the integration between a purpose-built storage software stack and a zoned Flash SSD, including block level benchmark results and system level, application benchmark results compared to the same software stack using a near identical FTL-based SSD.

Block level benchmarks (fio):


  • Over 3x improvement in throughput
  • 50x improvement in tail latencies
  • Estimated 3x improvement in Flash wear out
    …all at the same time

System level benchmarks (MySQL®/SysBench):


  • Over 65% improvement in tps
  • Over 22x improvement in tail latencies
  • Estimated 3x improvement in Flash wear out
    …all at the same time

While zoned Flash SSDs can provide significant improvements in system performance, integrating them with a host storage management layer often requires extensive software modifications and development efforts. This document provides an overview of how Radian’s Zoned Flash SSD, combined with the flexible architecture of SoftwAre Log Structured Array (SALSA) [1], developed by scientists at IBM Research enabled achieving dramatic system performance improvements with minimal development efforts.


SALSA is a versatile, host resident translation layer that can virtualize multiple storage devices (SSDs or HDDs) and be configured to adapt to specific workloads. Targeting the backend of Software-Defined Storage (SDS) frameworks, SALSA can expose a Linux block device that can either be used directly by unmodified applications, or mounted by a traditional Linux filesystem.

Radian Zoned Flash SSD

The RMS-350 is a U.2 NVMe SSD based upon Radian Memory Systems’ implementation of Zoned Namespaces (ZNS) that provides idealized, configurable Flash SSD zones. Routine Flash management processes are cooperative between the device and the host to provide superior system level performance and efficiencies than can be achieved with FTL-based SSDs.

See highlights on how Radian’s functionality specifically helped enable Rapid Integration and Exceptional Performance with SALSA


Complete case study document:

1434855273_FEZ-03  Case Study: IBM Research’s integration of Radian Zoned Flash SSD with SALSA storage software stack 

About IBM Research

IBM Research is one of the world’s largest and most influential corporate research labs, with more than 3,000 researchers in 19 locations across six continents. We play the long game, investing now in tomorrow’s breakthroughs. Watson, the world’s first cognitive system, is the fruit of over 50 years of IBM research in artificial intelligence. Today, it forms a core part of IBM’s business.  Our scientists are charting the future of artificial intelligence, breakthroughs like quantum computing, how blockchain will reshape the enterprise and much more. We are dedicated to applying AI and science to industry challenges, whether it’s discovering a new way for doctors to help patients, teaming with environmentalists to clean up our waterways or enabling retailers to personalize customer service.

[1] Ioannou N., Kourtis K., and Koltsidas I. .Elevating Commodity Storage with the SALSA Host Translation Layer. International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems 2018 (MASCOTS’18)