| Solid-state Drives (SSDs) have been on the edges of the storage market for years, but high prices have kept them from being considered for mainstream storage.
Among the most widely used forms of solid state is NAND flash, which is in consumer devices like iPods and smartphones. Price drops in flash's raw materials and consumer awareness are stirring interest in NAND flash applications for the enterprise.
SSD's fast read performance, durability and lower power consumption are also driving vendor investment. EMC became the first major vendor to include flash drives in its arrays when it added STEC's solid-state technology to Symmetrix in early 2008.
"It's not just a couple of barely funded startups. I'm seeing smoke coming from all areas," says analyst Mark Peters, analyst at Enterprise Strategy Group in Milford, MA. "Whether it's laptops or Symmetrix, you see movements on all fronts."
Texas Memory Systems has been in the DRAM-based storage business for years. It recently extended into NAND flash, according to Woody Hutsell, executive VP. "[Flash] has transitioned so that it does really have mainstream potential," he says. Increased demand, especially from the consumer side, is helping make flash more realistic for enterprises. Hutsell estimates that chip costs have dropped 30% in the past few years.
Solid state's run at enterprise storage is aided by an industry hot topic: greenness. With no mechanical parts, NAND flash technology is inherently more energy efficient. When data centers need performance, they buy more hard disk drives, says Hutsell. "Those hard disk drives are very power hungry," he says. "In order to get performance, you have outrageous power consumption and cooling requirements."
Flash's read performance outshines that of hard disk drives, but one of solid state's chronic weaknesses is its slower write times. "There will forever be a write challenge," says Pat Wilkison, VP of marketing and business development at STEC. "The only way to work around that is having very elaborate NAND controller technology within these SSDs." EMC's controller technology, says Bob Wambach, senior director, Symmetrix marketing, "includes wear-leveling algorithms to redistribute workload evenly among all cells in the drive, and substitute cells that can be used for both wear leveling and cell healing."
Other NAND controller developments include media vendor Imation partnering with Mtronstorage Technology Co. (which makes SSD controllers), and newcomers Pliant and Fusion-io working on SSD products.
Amyl Ahola, CEO at Pliant Technology, says its proprietary flash architecture will include a controller and related firmware, shipping in Q4 of this year. "What flash will be doing," he says, "is in many cases taking over high-performing applications and relegating hard drives to what they're best at: very low-cost storage and sequential operations as opposed to random operations."
Fusion-io's NAND flash product will debut later in 2008, says CTO David Flynn. He thinks the logical way to use flash isn't behind a RAID controller, but plugged into the server. "The pain point is this disparity between the CPU and memory complex, and the disk storage on the back," he says.
But solid state isn't a must-have for storage managers yet. Despite dropping costs, it's still too expensive for many businesses. "It totally makes sense" to use flash, says Bill Montgomery, manager of information systems at Lulu.com, but cost is the major barrier. "It's barely on the edge of our radar."
Peters sees a tipping point at which people will be willing to pay more for flash. "You can have either a solid-state device that is very small, very fast, with very low energy consumption, or you can have spinning things," he says. "Ultimately, why do you need things that spin?"