SATA-IO recently announced a new specification for an PCIe and SATA-IO specification (better described in the presentation) that will provide a SATA device interface directly connected to a server’s PCIe bus.
The new working specification offers either 8Gbps or 16Gbps depending on the number of PCIe lanes being used and provides a new PCIe/SATA-IO plug configuration.
While this may be a boon to normal SATA-IO disk drives I see the real advantage lies with an easier interface for PCIe based NAND storage cards or Hybrid disk drives.
New generation of PCIe SSDs based on SATA Express
For example, previously if you wanted to produce a PCIe NAND storage card, you either had to surround this with IO drivers to provide storage/cache interfaces (such as FusionIO) or provide enough smarts on the card to emulate an IO controller along with the backend storage device (see my post on OCZ’s new bootable PCIe Z-drive). With the new SATA Express interface, one no longer needs to provide any additional smarts with the PCIe card as long as you can support SATA Express.
It would seem that SATA Express would be the best of all worlds.
- If you wanted a directly accessed SATA SSD you could plug it in to your SATA-IO controller
- If you wanted networked SATA SSDs you could plug it into your storage array.
- If you wanted even better performance than either of those two alternatives you could plug the SATA SSD directly into the PCIe bus with the PCIe/SATA-IO interface.
Of course supporting SATA Express will take additional smarts on the part of any SATA-IO device but with all new SATA devices supporting the new interface, additional cost differentials should shrink substantially.
The PCIe/SATA-IO plug design is just a concept now but SATA expects to have the specification finalized by year end with product availability near the end of 2012. The SATA-IO organization have designated the SATA Express standard to be part of SATA 3.2.
One other new capability is being introduced with SATA 3.2, specifically a µSATA specification designed to provide storage for embedded system applications.
The prior generation SATA 3.1, coming out in products soon, includes the mSATA interface specification for mobile device storage and the USM SATA interface specification for consumer electronics storage. And as most should recall, SATA 3.0 provided 6Gbps data transfer rates for SATA storage devices.
Can “SAS Express” be far behind?