Hitachi also unveiled a new 8U chassis built specifically for the Virtual Storage Platform. Each 2U flash tray contains 12, 1.6 terabyte (TB) flash modules. Each 8U flash chassis can hold up to four flash trays. One VSP system can hold four new flash chassis for a total of 6.4 TB to 76.8 TB per flash tray, and 307.2 TB of flash per system.
Roberto Basilio, HDS' vice president for Infrastructure Platforms Product Management, said he expects HDS to have a 3.2 TB flash module within six months that will allow a VSP to support 153.6 TB of flash. He said other HDS storage arrays will also use the flash technology down the road.
Henry Baltazar, a senior analyst with 451 Research, said the Hitachi Accelerated Flash module does not look like a typical flash array.
"This is a proprietary design," Baltazar said, "and they don't intend on making this available to other storage vendors. You're not going to see this in a NetApp box."
Violin Memory Inc. and Texas Memory Systems (now part of IBM Corp.) also designed and use their own flash controllers, Baltazar said. Other flash storage providers such as Pure Storage Inc., Whiptail and Kaminario Inc. use commodity controllers and standard-form drives.
Basilio claimed a number of technologies used in its flash controller enable it to achieve higher performance and better power efficiency than other SSDs on the market today, including those that HDS used in its storage arrays before developing its own.
"We are able to achieve more than four times the sustained performance when compared to the same activity against traditional small form factor or large form factor SAS [Serial-Attached SCSI] solid state drives like we used in the past," Basilio said.
The HDS flash memory controller is a multi-core, high-bandwidth architecture that uses block and page mapping, wear leveling, an endurance manager, and inline write compression that results in up to 94% write reduction.
"We don't change the characteristics of the NAND itself," Basilio said. "We change the way we use the NAND. The fewer times we touch the NAND, the better the resilience of that component."
HDS explained its flash integration strategy, introduced the flash controller, and released a flash acceleration microcode update for the VSP on Aug. 23.
Baltazar said the phased introduction of HDS flash technology and product launch puzzled many in the storage industry because it went against what most of its rivals have done. Every major storage vendor already has SSD options available for its storage arrays and some have several options for implementing flash. EMC offers flash in its array and server-based flash, and is due to release an all-flash array (Project X) and PCIe-based flash for shared storage (Project Thunder) next year. NetApp offers Flash Pools for array-based SSD caching, Flash Accel server flash software, and controller-based Flash Cache.
While others have acquired or partnered for their flash hardware, HDS is engineering its own.
"It took longer to get to market," Baltazar said of HDS. "But what they are trying [to say] with this technology is, 'Hey, now we have high performance, and we're going to wrap it around the flagship platform that our customer base likes and is very familiar with.'"
Basilio indicated that Hitachi had already shipped product to early adopter customers. He estimated the final street price of the Accelerated Flash storage module will be $8 to $9 per GB.