The new 2.5-inch drives are based on a controller design for faster I/O performance and low energy consumption. The Lightning LB 200M is a 200 GB drive and the Lightning LB 400M is 400 GB, a significant capacity bump over the 150 GB maximum of Pliant's 2.5-inch SLC drives. The MLC drives have 3 Gbps SAS interfaces and four duplex ports. The drives are sampling with potential server and storage array OEM partners, and are expected to be available through Pliant's channel partners next month.
SLC drives perform at higher levels than MLC drives, but cost significantly more. With price a major hurdle to enterprise SSD adoption, vendors have been working on improving the performance of MLC drives while maintaining their cost advantage.
Greg Goelz, Pliant Technology's vice president of marketing, said Pliant's MLC drives don't use a write cache, making their performance more predictable.
Pliant claims the Lightning LB 200M can perform at 20,000 total sustained IOPs, and more than 240 MBps of sustained transfer reads with 100 MBps of sustained transfer writes. The Lightning LB 400M is rated at 25,000 total sustained IOPs, and greater than 270 MBps sustained transfer reads and more than 100MBps of sustained transfer writes. With a mix of 70% reads and 30% writes of 4 KB data blocks, Pliant claims the 400M can reach 10,000 random IOPS and the 200M can hit 8,000 IOPS.
By comparison, Pliant's Lightning LB 150S 150 GB SLC drive can reach 120,000 sustained IOPS, 420 MBps of sustained transfer reads and 220 MBps of sustained transfer writes. However, Goelz said SLC drives are twice as expensive when measured by dollars per gigabyte.
Goelz sees SLC and MLC forming storage tiers based on price and capacity the way hard disk drives do today.
"There is room for SLC and MLC," Goelz said. "I think they could be separate tiers. Today, hard disk drives are the building blocks of different types of storage configurations. Where we see the market going is to mix hard disk drives for dollars per gigabyte or pennies per gigabyte capacity points with solid-state drives offering performance requirements. Between the two, you can build hybrid configurations. You can build bigger, higher performance systems for less money."
Jim Handy, SSD analyst at semiconductor industry analyst firm Objective Analysis, said he thinks it's just a matter of time until MLC flash catches on in the enterprise.
"Although the differences between SLC and MLC NAND flash chips look very straightforward when comparing the technical specifications, once these chips are put behind an SSD's controller everything changes," he said. "The MLC chips' slow writes become less of a burden and the reliability differences become far less significant. Objective Analysis expects MLC to become a very significant part of the enterprise SSD landscape in the near future."
Pliant has a distributor relationship with Bell Micro, which was acquired by Avnet Inc. in June. Pliant Technology is also looking to compete with STEC Inc. and others for OEM deals.
Objective Analysis' Handy said there aren't many vendors with similar SAS interface products. STEC is adding a SAS product line to go with its Fibre Channel SSDs and Hitachi Global Storage Technologies (Hitachi GST) is working on putting a SAS interface on an Intel SSD architecture. "It was to have been out by now, but [the shipping data] slipped," he said. "Pliant decided to go after the SAS market because the competition is few and far between."
Pliant Technology's Lightning enterprise flash disk (EFD) product family includes the 2.5-inch LB 150S, as well as the 2.5-inch LS 150S and LS 300S drives.