SATA group creates new high-speed storage spec

The Serial ATA International Organization (SATA-IO) announced a new PCI Express (PCIe)-based interconnect specification that aims to boost interface throughput of solid state drive (SSD) technology from 6GB/sec to 8Gb/sec and 16Gb/sec.

The group said the new SATA Express specification, which it expects to release by the end of the year, protects investments in current SATA and PCIe products because it's a hybrid of both and still looks like SATA to the host system.

An artist's rendition of SATA Express cabling

The current SATA 3.0 spec offers up to 6Gbit/sec throughput on a single channel, which is sufficient for most hardware interconnects, such as hard disk drives and mini-flash drive products.

Consumer and data center SSDs and hybrid drives that consist of flash memory and traditional spinning hard drives, however, can possess multiple internal channels to the flash memory chips. Multiple channels can quickly saturate a 6Gbit/sec I/O interconnect, said Mladen Luksic, president of SATA-IO.

"We had two choices. Either increase the SATA speed or find another [hybrid] solution that can be available today and be cost and technology compatible with legacy SATA environments," he said.

Because consumer and corporate SSDs are still a relatively small portion of the overall SATA device market, SATA-IO couldn't justify development of new SATA interconnect speeds, Luksic said, because it would "burden all other applications that are perfectly happy with 6Gbit/sec SATA."

The SATA Express specification combines the physical interface of PCI Express and moves the SATA controller from the host and into the SSD. "So to the OS and the application on the host side, the SATA Express device still looks like a SATA device. But in between it's PCIe physical connectivity," he said.

The specification will define new device and motherboard connectors that will support both new SATA Express and current SATA devices.

An artist's rendition of the SATA Express motherboard connector

SATA Express will offer either one or two PCIe lanes, meaning devices will be able to support either 8Gbit/sec or 16Gbit/sec throughput, depending on how many lanes are used.

"It's scalable because PCIe is scalable in terms of adding more lanes," Luksid said. "So if there is a need to satisfy higher performance requirements of SSDs, we can do that simply by putting more lanes in rather than increasing the raw speed of the physical interconnectivity."

Lucas Mearian covers storage, disaster recovery and business continuity, financial services infrastructure and health care IT for Computerworld. Follow Lucas on Twitter at @lucasmearian, or subscribe to Lucas's RSS feed . His e-mail address is lmearian@computerworld.com.