Introduction to the new SFF8639 Connector for Backplanes. SFF 8639 is an extension of the 8482 SAS Connector which has higher signal quality requirements (to support 12Gb/s SAS and gen 3 PCIe) and adds support for SATA Express and 4 lanes of MultiLink SAS or PCI Express.
The connector has a total of 6 High Speed signal paths, strangely each specification only ever uses up to 4 of them at any time.
The standard defines a backplane connector that is designed to support the following interfaces:
Whilst the connector is physically compatible with all of the drive types listed above, systems using this connector will probably only support a subset of these interfaces.