Now most storage array vendors have automated tiering software. And with Seagate’s launch of its Pulsar SSDs today, several of the leading drive makers have MLC devices to go with the more expensive single layer cell (SLC) drives on the market. So will SSDs now ramp quickly in the enterprise?

Probably not, although their use will certainly increase at a greater rate than they been.

Gartner analyst Joseph Unsworth said the enterprise SSD market went from around 320,000 units and $485 million in sales in 2009 to over 1 million units and over $1 billion in sales last year. He forecasts 9.4 million units and $4.2 billion in sales by 2015.

Seagate’s internal projections see SSDs catching up to 3.5-inch hard drives in the enterprise in units shipped in 20013 but not making much of a dent on 2.5-inch hard drives.

“The enterprise doesn’t turn on a dime,” Unsworth said. “There are long qualifications and there’s still confusion from end users. They know SSDs are important, but traditional data center professionals aren’t saying ‘We have to have this.’ They’re deployed in application workloads where they make most sense, like search, social media, data warehousing and stream video.”

MLC drives are cheaper than SLC drives but they wear out a lot faster. Until recently they were limited to consumer devices but are working into the enterprise. IBM said it will ship STEC MLC drives on midrange and enterprise storage arrays, and Seagate’s MLC drives will likely find their way into arrays from EMC and other array vendors.

Still, Unsworth added that pricing is decreasing at a slower rate for SSDs in storage systems than in servers.

He said the price erosion for the server side is forecasted for about 34% over the next five years with storage expected to drop about 30%. “It will take more MLC, more [product] competition and more scale to bring prices down,” he said.