Serial ATA is about to get a whole lot quicker. The SATA-IO (the folks in charge of the standard) has ratified the SATA 3.2 specification, which uses PCI Express to enable transfer rates as high as 2GB/s. The spec also introduces a number of other enhancements, covering everything from embedded storage to hybrid hard drives.
Here’s the skinny on SATA Express, which enables the new spec’s speed improvements, straight from the official press release (PDF):
Initially introduced in January 2013, the SATA Express specification enables a client storage ecosystem that allows SATA and PCIe solutions to coexist. A host implemented to this specification will connect to and function with either a SATA or PCIe storage device. PCIe technology enables increased interface speeds of up to 2GB/s (2 lanes of PCIe 3.0), compared with today’s SATA technology at 0.6GB/s (6Gb/s). The increased speed of PCIe provides a cost-effective solution for optimizing performance of Solid State Drives (SSDs) and emerging SSHDs. Storage devices not requiring the increased speed of PCIe, such as traditional hard disk drives (HDDs) and optical drives, will continue to be supported by SATA.
SATA 3.2 also introduces the following features:
- M.2, a small form factor much like mSATA, except with support for "a variety of applications including WiFi, WWAN, USB, PCIe and SATA."
- microSSD, a standard that allows "single-chip SATA implementations" for use as embedded storage.
- Slimmer USM modules for consumer electronics devices.
- A deeper sleep mode called DevSleep, which can "almost completely" shut down a drive.
- Transitional Energy Reporting, which helps improve power management by transmitting more detailed information about SATA devices.
- Hybrid Information, a scheme that lets systems "communicate data caching information" to hybrid hard drives (a.k.a. SSHDs) in order to boost performance. (Hybrid drives haven’t done too well in our benchmarks thus far.)
- Rebuild Assist, which "speeds the data reconstruction process in RAID configurations."
Yeah, those are nice, but I’m definitely more excited about the performance boost. PCI Express SSDs with eye-popping transfer rates already exist, but on the desktop, they fit on full-sized PCIe expansion cards. Those can limit your expansion options—especially inside small-form-factor PCs. According to this presentation, SATA 3.2 will bring PCIe connectivity to 2.5" drives much like those on the market today. It looks like connectors will be a little different, though.