LSI Corp. today launched a NAND Flash PCI Express (PCIe) card with a 6 Gbps SAS interface as well as 6 Gbps SAS switches that connect servers to direct-attached storage (DAS). The solid-state Flash card and switches are shipping to OEM partners, and LSI plans to sell the Flash card direct later this year.
The LSI SSS6200, which plugs into the PCIe port on industry-standard servers, will compete with PCIe Flash card maker Fusion-io Inc. Unlike Fusion-io's PCIe cards, LSI uses a SAS controller as an interface between the server and the card's Flash modules. Seagate Technology supplies the SSD modules for the LSI PCIe card.
"The advantage of using a SAS interface is that it's a very robust standards-based interface, which covers virtually all operating systems and applications," most of which understand SCSI commands, said J.B. Baker, LSI's product manager .
Jeff Janukowicz, research manager, hard disk drive components and solid-state disk drives at Framingham, Mass.-based IDC, said some solid-state storage vendors have used field-programmable gate arrays (FPGAs) where LSI places its controller ASIC with the SSS6200. "A lot of this comes down to cost — an ASIC vs. a higher cost FPGA could lower the overall cost [of the product], which is the key barrier to SSD [solid-state drive] adoption so far," he said.
Fusion-io marketing communications director Robert Brumfield defended his company's approach, saying it delivers greater application acceleration than LSI's architecture.
"Today all data ultimately goes through the PCIe system bus," Brumfield wrote in an email to SearchStorage.com. "A SAS storage bus approach to connecting NAND Flash to a system, while it may show well under storage benchmarks, will not achieve the same level of application acceleration that Fusion-io's memory controller approach is capable of achieving,"
The cards will ship with up to 300 GB NAND capacity on board. LSI claims the card will deliver up to 200,000 sequential IOPS with a 4 K block size and up to 150,000 4 K random IOPS. According to an LSI data sheet, the drive "is available with complete management infrastructure for extensive monitoring including health, error rate, [and] failure monitoring."
LSI marketing materials mention "software optimized for SSD performance," but LSI officials declined to comment on the details of that optimization. Other solid-state storage vendors have disclosed details of wear-leveling software that they claim prolongs the life of the NAND medium or makes random writes to the drive more efficient. Here, LSI officials said that wear leveling is performed at the NAND level below the LSI SAS controller, and that the NAND chips are provided by another vendor. The officials also declined to disclose who makes the NAND chips or what wear-leveling features they offer.
LSI has a longstanding and close partnership with Seagate, whose Pulsar SSD came to market last December with an LSI controller embedded. Those products are shipping with a SATA interface, and industry experts are waiting for Seagate to offer more storage interfaces with Pulsar to compete with the likes of STEC Inc., which offers multiple interfaces to OEMs.
Greg Schulz, founder and senior analyst at Stillwater, Minn.-based StorageIO Group, said he wouldn't be surprised to see a SAS version of Pulsar arise from this LSI announcement. "Let's put it this way, everything in the industry is going to SAS, and Seagate and LSI already work very closely together," he said.
Meanwhile, "Fusion-io is probably the best-known solid-state storage vendor in the industry so far, maybe even better known than STEC because STEC ships through OEMs," Schulz said. "But LSI has such a large install base already for its RAID cards that this will make for a very, very interesting game [in solid-state storage] now."
The solid-state storage "hype cycle" of 2009 has passed, leaving it unclear how robust the market will be for solid-state storage this year. STEC and the rest of the solid-state storage market had a rude awakening around the end of 2009 and the start of this year, beginning with a report from STEC that EMC -- its largest OEM partner -- had a backlog of STEC inventory.
"The focus for the next year or so will be making good use of a small amount of what still is, frankly, expensive stuff," said Mark Peters, a senior analyst at Milford, Mass.-based Enterprise Strategy Group (ESG). "It's all about using Flash capacity as 'pixie dust' to improve performance across a whole system."
Given that, Peters said he'd like to hear more from LSI about the optimization software included with the SSS6200. "Knowing where to sprinkle [solid-state] 'pixie dust' effectively through management software will separate the wheat from the chaff," he said.
6 Gbps SAS switch an appeal to smaller businesses
Also included in this announcement from LSI is its first SAS6100 6 Gbps switch released to OEMs. LSI developed a 3 Gbps SAS switch that it never sold, but 6 Gbps SAS includes more granular support for zoning and other features that industry analysts claim will make SAS more competitive with Fibre Channel (FC) drives.
But while 6 Gbps SAS drives will probably replace FC disk drives in the long run, whether 6 Gbps SAS could become the network interface is a different question. SAS back ends can be connected with FC because both are based on SCSI, and at 8 Gbps, FC is already outpacing SAS as a network protocol. Fibre Channel over Ethernet (FCoE) is also expected to be the next-generation network of choice among large enterprises.
Bob Laliberte, an ESG senior analyst, said 6 Gbps SAS networks may appeal to smaller businesses. "A lot of large shops are sticking with what they know — the opportunity for 6 Gbps SAS is in low-end environments without networked storage," he said.