TORONTO — With triple-level-cell (TLC) NAND adoption poised for growth, Silicon Motion is looking to accelerate that trend with the introduction of its latest SSD controller at the Flash Memory Summit this week. The company says its merchant SM2256 6 Gbit/s SSD controller supporting 1x/1y/1z TLC NAND is the first of its kind and builds on the capabilities of its first-generation SATA 3 SSD controller introduced last year.
Robert Fan, Silicon Motion’s VP/GM SMI U.S.A., says the SM2256 is designed to support a broad array of TLC NAND in client devices, as well as 3D NAND, and will give OEMs a leg up in bringing new TLC NAND SSD offerings to market by providing a complete package, including firmware. He says the new controller technology will help bring the price of TLC NAND SSDs down for more widespread use in client devices, including laptops, which still predominately ship with spinning disk.
A report released earlier this year by IHS Technology found the HDD segment is struggling due to the rise of smartphones and tablets, which is particularly affecting the consumer PC market. The SSD market, however, is growing thanks to a recent decrease in the cost of SSDs and a resulting higher adoption of the drives by ultrabooks and ultrathin PCs.
One of the key challenges for TLC NAND is endurance, which Fan says can be addressed with the right controller technology, and this in turn will foster further adoption of TLC NAND. One of the features included with its SM2256 controller is the company’s NANDXtend Technology, which, he says, can provide three times the P/E cycle of TLC NAND and also overcomes endurance and data retention concerns.
Performance-wise, the SM2256 features sequential read of up to 524 Mbit/s and sequential write of up 400 Mbit/s, with random reads of up to 90,000 IOPS and random writes of up to 70,000 IOPS. Fan says a complete design kit for the SM2256 is available now, including a controller datasheet, evaluation boards, schematics, and firmware. It can also support customer firmware. Silicon Motion expects products using the SM2256 controller will be available by early next year.
Jim Handy, principal analyst at Objective Analysis, says Silicon Motion is well positioned to gain traction in this segment where Seagate, having acquired LSI, and Marvell is well established. While Silicon Motion did not immediately jump on the SATA SSD controller bandwagon, he says, it’s been in the space since last year and brings TLC expertise to the table thanks to its experience with controllers for USB devices, which tend to use TLC.
Handy says he anticipated growth of TLC a year ago, and says it's following a similar path to MLC flash, which was initially thought not to be a viable option for client SSDs. However, after finding its way into that segment, it eventually made its way into the enterprise. He sees TLC following the same trend -- adoption in client SSDs in the near future, with eventual entry into enterprise devices, although that’s unlikely to happen this year or next.
Meanwhile, memory vendors are looking to improve overall NAND cost competitiveness. Micron, for example, is working on its 16 nm TLC roadmap and expects to see component samples of the 16 nm TLC by the end of the year with client-based TLC SSD expected by spring of 2015. Samsung introduced 64 Gbit NAND flash using TLC and 21 nm process technology in fall of 2012 and announced production of advanced NAND flash devices with 128 Gbit TLC NAND using 10 nm class process technology in May 2013.