Innodisk Enhances Endurance of MLC NAND Flash to 30K Cycles

Innodisk Introduces iSLC Technology for Solid-State Drives

by Anton Shilov
03/28/2013 | 11:37 PM

Innodisk, a designer and manufacturer of solid-state drives for industrial applications, said it has developed a way to dramatically enhance endurance of conventional multi-level cell (MLC) NAND flash memory and bring it closer to the current-generation single-level cell NAND flash. The technology relies on patented flash management algorithms and can be adopted to different types of chips from different manufacturers.

 

Traditionally, MLC NAND flash could endure around 10 000 write cycles per bit, whereas SLC NAND flash could endure around 100 000 write cycles per bit. Modern MLC, which is produced using 19nm – 20nm process technology, can endure 3 – 5 thousand rewrite cycles, whereas some SLC chips are rated to endure “only” 60 thousand of rewrites. In addition, SLC memory by design offers higher performance than MLC. Unfortunately, it is also considerably more expensive than MLC. According to Innodisk, its iSLC technology offers performance, reliability and endurance comparable to SLC NAND flash, but at considerably lower cost.

 
An SLC-based SSD from HGST. Image for illustrative purposes only.

iSLC firmware technology reprograms the two bits per cell of MLC into one bit per cell, which increases the sensitivity delta between each level. This practice enables the NAND flash to perform similar to an SLC flash-based solution. The average endurance of iSLC can surpass 30 000 program/erase (P/E) cycles, which increases the lifespan of the drive over MLC flash by a multitude. Additionally, write performance for iSLC is about 70% faster than MLC on Serial ATA II, according to the company.

Innodisk has designed iSLC to perform as close as possible to SLC flash, with a price point similar to MLC flash-based products. This technological development offers a cost-effective way for industrial applications, such as kiosks and POS, to perform at a high capacity while still keeping a tight control on expenditures.

With endurance of 30 000 PE cycles, 32GB SSDs with iSLC can sustain 32GB drive writes per day for over 7 years, delivering a lifespan that is suitable for industrial and enterprise applications.

The first iSLC-based products from Innodisk are projected to hit the market in the second quarter of 2013. Given the fact that iSLC essentially requires two times more physical NAND flash memory to provide mainstream capacities (e.g., over 64GB required to make a 32GB SSD), do not expect iSLC-based SSDs to cost in line with mainstream solid-state drives.