Texas Memory Systems (TMS) has launched a tiered, high-capacity DRAM/flash hybrid solid-state disk (SSD) array that can store up to 512 GB of data on DRAM-based solid-state storage and uses NAND Flash storage as backup media.
A previous product, the RamSan-500, also featured a combination of DRAM and Flash memory, but its primary media was Flash, with DRAM cache. The RamSan-440 is the first product that uses DRAM as primary, Tier 1 storage, with RAIDed flash acting as "bulk" Tier 2 backup storage. With the expanded solid-state capacity, TMS claims the system can deliver up to 600,000 IOPS.
The new system is also the first to ship with TMS' new IO² feature, which the company said can make data available within 30 seconds on start up. Otherwise, it can take up to two hours to repopulate the RAM capacity if it has to reload data from hard drives. IO² automatically repopulates the RAM cache much quicker from flash. The RamSan-440 is also the only SSD to incorporate both IBM Chipkill technology and RAID-protected RAM to protect against chip or board failures.
Users said the scalability, which may seem small in hard drive terms, but is actually close to four times the capacty of previous models that scaled to 64 GB and 128 GB, is the biggest selling point of the new array. "To be able to get up to 1 TB of solid-state disk [including the NAND backup capacity] for the same price is a no-brainer," said Burzin Engineer, vice president of technology for Shopzilla. The online retailer already uses the RamSan-300 behind OnStor clustered NAS gateways for its most demanding applications.
The added capacity sounds particularly good for data warehousing applications, Engineer said. "Right now we have to plan out data analytics projects very carefully. The data analytics guys could just go hog-wild on a system like this."
While such a complex system might seem like overkill for a market still wary of SSD deployment in enterprise systems, DRAM has been around a lot longer than flash-based disk drives, said IDC analyst Jeff Janukowicz. "We see it a lot in financial institutions and companies that do e-commerce," he said. Unlike NAND that can often have slower write speeds than reads, "RAM balances between the read and write aspects of the data set."
Some observers think this approach might make more sense than a hybrid device format, like EMC's Symmetrix disk arrays with SSDs from Stec Inc. "This product makes a compelling business case for the storage of very small amounts of data (2%-3%) that gets hammered with most of the reads and writes, such as database indexes, Exchange store and forward queue, and virus definition libraries," said Steve Mackie, president of storage consulting firm Storage Strategies. "If SSD can take a big enough chunk of the highest performance burden, an enterprise may be able to avoid having to buy the very pricey SIMM-like products and still meet user performance requirements much more economically."
However, other analysts said everyone is missing the point. "This system appears to be an interesting repackaging of SSD storage for the very high end and will be valuable for the limited number of companies that really care about performance at that end of the spectrum, are willing to work with an additional vendor and are sophisticated enough to do the performance analytics on where it fits in their environment," said Forrester Research analyst Andrew Reichman. "Most companies would rather have a product from their trusted vendor that … comes with some analytics [pointing] to which data sets belong on SSD." The RamSan-440 is available now at a starting price of $150,000 for a unit with 256 GB of DRAM and $275,000 for a unit with 512 GB.