Double Signaling Speed for Serial ATA
While both are arguably being overshadowed right now by the imminent arrival of PCI Express, hardware makers say there’s lots of life left in the original PCI bus and in last year’s debutante, the Serial ATA interface. Both reached milestones with revised specifications this week.
The PCI Special Interest Group has released version 3.0 of what debuted in 1992 and is now known as Conventional PCI. Building on version 2.3, the new spec completes the migration from 5.0-volt to today’s industry-standard 3.3-volt slots by dropping support for 5.0V-only keyed add-in cards, though cards keyed for both 5.0V and 3.3V slots continue to be supported. PCI 3.0 also incorporates some errata and engineering change notifications from version 2.3, and supports multiple bus specifications including PCI 66, Mini PCI, PCI-X, and Low Profile PCI.
Meanwhile, the Serial ATA Working Group has completed and begun release-candidate ratification for a second-generation SATA signaling speed — 3Gbps (300MB/sec), double that of original Serial ATA’s 1.5G gigabits per second. A selection of SATA products supporting 3Gbps signaling speeds have already been announced, and those that comply with the new spec — which also defines a higher-power PHY for longer-haul box-to-box rather than direct-disk-drive connections in data centers — should begin to be marketed as 3Gbps Serial ATA ware within about 30 days.
While the new signaling rates require no new cables and connectors, Volume 2 of the Serial ATA cables and connectors specification has also appeared, with new options including a consumer-friendly connection for external storage devices and a multilane setup for connecting multiple SATA channels between chassis in a data center. Products using the new hookups are expected by the end of the year.