LSI Corp. this week demonstrated its latest LSI SandForce flash controller technology innovations at the Flash Memory Summit. LSI has shown some capabilities of the next-generation SandForce SSD controllers as well as improved SandForce SF2000-series processors with improved features.
LSI demonstrations include LSI SHIELD technology, an advanced error-correction method designed to deliver enterprise-class SSD endurance and data integrity, even while using less expensive flash memory that typically has higher error rates. SHIELD technology is a unique implementation of low-density parity-check (LDPC) code and digital signal processing (DSP) that will be available in next-generation SandForce flash controllers. The technology combines hard-decision, soft-decision and DSP to provide a comprehensive error correction code (ECC) solution that is optimized for flash memory.
LSI SHIELD technology offers advantages over existing LDPC implementations by uniquely combining several features:
- Adaptive code rate: dynamically balances performance and reliability over the life of the SSD;
- Smart handling of transient noise: reduces overall LDPC latency for improved ECC efficiency;
- Multi-level ECC schema: judiciously applies stronger levels of ECC to minimize latency while maintaining optimal flash performance;
The demonstration of SHIELD technology at Flash Memory Summit showcased the error-correction advantages of SHIELD technology versus existing LDPC and Bose-Chaudhuri-Hocquenghem (BCH) code methods through a comparison of the three technologies based on various raw bit-error rates (RBER) from the flash.
“While the value proposition of NAND flash memory grows and is driving the adoption of flash-based storage solutions, the tradeoff is that today’s smaller fabrication geometries come with lower reliability and a shorter lifespan. LSI SHIELD technology helps solve these challenges with advanced error correction that is optimized for SSDs and transforms the latest NAND flash memory into a more robust storage solution,” said Huibert Verhoeven, vice president and general manager of flash components division at LSI.
LSI also demonstrated advantages of DuraWrite Virtual Capacity (DVC) technology, a unique SandForce flash controller feature that extends the available storage capacity for typical data beyond the physical capacity of the underlying flash memory. By increasing storage capacity for the same physical flash memory, DVC helps to reduce the cost per gigabyte of delivered capacity to the user. With typical database applications, LSI internal testing has shown that DVC can be used to more than triple the capacity for storing user data. The DVC feature will be demonstrated showing various applications of the technology.
Finally, LSI showcased new SandForce SF-2000-series controllers that now support Toshiba’s second generation advanced 19nm NAND flash memory (A19nm), enabling SSD manufacturers to produce more affordable SSD products. The demo will showcase an SSD with Toshiba A19nm flash technology set up as a secondary drive to show typical file-transfer operations.
“We have worked closely with LSI to enable this first public demonstration of Toshiba second generation advanced 19nm (A19nm) NAND in a solid state drive. The LSI SandForce flash controller design provides the flexibility to integrate our A19nm NAND flash technology which is sure to play a prominent role in the solid-state storage market,” said Scott Nelson, senior vice president of the memory business unit of TAEC (Toshiba America Electronic Components).