Innodisk Initiates 2013 Trends in Industrial Flash Memory

According to a report released by information and analytics provider IHS iSuppli, unit shipments of SSDs throughout the year 2012 increased 1.29-fold from 2011.

However, in the industrial control segment, the growth of SSDs is accompanied with dramatic changes. Facing up to the changes in the marketplace, Innodisk Corp., SSD provider for industrial applications, has prepared technical innovations to be released in the year 2013.

Adoption of MLC flash memory has grown at a pace faster than expected. Yet, MLC flash has inherent limitations as a result of manufacturing yield issues, which need to be remedied by back-end designs of SSD devices. Innodisk has prepared solutions to solve these problems and further explored the potential of MLC flash.

Secondly, SATA-III, which nearly doubles the R/W speeds of SATA-II, has already become a mainstream data connection interface for consumer-grade products, and is currently emerging in the industrial application segment. Innodisk believes that SATA-III will definitely become mainstream for industrial SSDs in the future as well. During the past half year, it has taken an aggressive pace and allocated more R&D resources to develop SATA-III SSDs. The company introduced its first 2.5" SATA-III SSD product line in the first quarter of this year, and will release miniaturized SATADOM and mSATA products also based on SATA-III later this year.

On the other hand, the trend of miniaturization continues. With the assistance of the Next Generation Form Factor standard stipulated by Intel (Intel NGFF), which helps to multiply the R/W speeds of smaller mSATA products, some key players in the market have been encouraged to adopt miniaturization. Miniaturization will definitely become unstoppable in 2013. Innodisk, which has already gained a market foothold in producing miniaturized modules, with its product line called SATADOM based on patented pin 7 technology, will also introduce miniaturized products based on NGFF specification later this year.

Trend 1: Backend designs will determine
the overall performance of flash memory
The growth in popularity of SSDs and their increasing applications have resulted correspondingly in aggressive improvements in the flash memory manufacturing process, making flash memory much cheaper than ever. In the past, the industrial control segment preferred SLC) flash memory due to its high reliability. However,  MLC flash is now gaining an edge with much more competitive pricing. Many light industrial applications now opt for MLC memory, which has resulted in the quick rise of MLC in the industrial market.

Though having an advantage in pricing, MLC Flash is facing many challenges when it comes to adoption among the industrial segment. Most of these challenges originate from the innate limitations of MLC, and the most fatal ones are its inferior reliability and endurance. Because MLC flash memory requires more constrained voltage ranges, it is more susceptible to ECC errors than SLC flash memory and needs more ECC corrections to ensure accurate storage. Therefore, MLC Flash memory is less reliable than SLC and has a shorter data retention lifetime.

More notable but often neglected is the fact that, with the production process scaling of flash memory (to increase yield and reduce cost), MLC is facing quality degradation. When the process is scaled down from 3X nm to 2X nm, the Programming/Erase Cycle (P/E Cycle) of MLC flash memory drops for 60% from ~5k to ~3k. The process scaling has also resulted in the need for more ECC bits: 2X nm MLC flash requires 24 ECC bits, while 1X nm process requires 40 ECC bits-almost double.

When an increasing number of industrial customers prefer quality-degrading MLC flash devices over SLC out of cost concerns, design of the backend module house becomes important in remedying the disadvantages of MLC. Innodisk has developed a series of technologies to solve the innate disadvantages of MLC flash, such as using thermal sensors to aid in remedying MLC flash’s vulnerability to temperatures outside of its normal operating range. When a sensor detects the temperature dropping past a certain threshold, a thermal pad will start to heat up in order to maintain normal operating temperatures and ensure the reliability of the flash memory and the device.

Innodisk uses firmware and hardware design to optimize endurance and reliability of original manufacturers’ products. One example is the iSLC technology-based SSDs it introduced in the final quarter of last year, which enhanced the performance, reliability and endurance of MLC Flash through firmware design.

According to the technical aspects of flash memory, each MLC Flash cell can store 2 bits of information, representing 4 distinct states: 00,01,10,11; while SLC flash stores 1 bit value per cell, which can be interpreted as 2 distinct states: 0,1. Innodisk’s self-developed iSLC technology adjusts MLC-based flash firmware to allow each MLC flash cell to represent only 2 states, 0 or 1, similar to that of SLC flash.

Cc Wu, director of embedded flash division, says: "We have the outstanding ability for choosing the best MLC flash memory, and we know how to use our proprietary firmware technologies to allow our iSLC products to perform at almost the same level as SLC-based products with reliability and service lifetime similar to SLC-based products, all while maintaining a lower price."

On the other hand, a good storage device monitoring tool is also important. Innodisk’s newly revised iSMART 3.0 can monitor all storage devices in a system, allowing users to check R/W speeds and remaining life span of each storage device. This monitoring tool can also display storage device operation status and alert users of the remaining service lifetimes so that they can replace a disk in time. The latest iSMART version can also visualize SSD Wear-Leveling status with graphics.

Trend 2: SATA-III adoption is to rise
in industrial control applications in 2013
SATA-III (6.0 Gb/s) is a data connection interface standard stipulated by SATA Working Group in 2009 allowing for backward compatibility with SATA-II and SATA-I, which is already a main implementation for consumer products. However, in the area of industrial control, where reliability is a priority, SATA-II is still the norm.

However, as the SATA-III specification is implemented for years in the consumer market, relevant technologies are getting quite mature. Considering its theoretical 600MB/s high data transfer speed, Innodisk believe that SATA-III has become suitable for industrial applications.

Innodisk tested SATA-III SSD performance on a SATA-II platform, and found two-fold increase in R/W speeds of storage devices. It has spent half a year on developing SATA-III devices, including finding ways to implement slumber and sleep modes for power-efficiency purposes. Innodisk is slated to introduce its SATA-III product lines in the first half of this year, including SSD, SATADOM, mSATA, CFast, SATA Slim and NGFF.

Trend 3: Miniaturized devices will become mainstream
The miniaturization trend has been happening not only in the consumer market but also in the industrial control market as well. It is expected to become the norm in the industrial sector in this coming year.

Currently, industrial control applications ask for more space-saving host board designs, especially when an increasing number of mobile devices opt for smaller form factor designs that further constrain the space of host boards. Miniaturization is a trend that has been happening for years, with mSATA being the mainstream specification for miniaturized devices in the past. However, mSATA is not a good option for mass storage due to the constrained amount of flash memory that can be deployed on a printed circuit board (PCB).

Yet, the Next Generation Form Factor (NGFF) stipulated by Intel including the SSD slot standard will be able to ease space constraints and enable an increase in data transfer speeds, which will be helpful in developing more storage devices of 2GB-16GB capacities-currently the mainstream requirements in industrial control. NGFF has already been recognized and implemented by a number of memory manufacturers, and Innodisk will follow this new standard and introduce NGFF-based products in the second half of the year.

It utilizes its own technological know-how to develop storage devices and memory modules which meet the requirements of mission-critical applications in aerospace, national defense, factories and embedded systems, with unique functionalities, forms and firmware designs.