SCA-2 (Single Connect Attachment-2) connector system consists of device plugs (at HDD) and vertical receptacles(at backplane), compliant with Small Form Factor (SFF) standard SFF-8451.
40-position backplane receptacles are designed to accept Fibre Channel drives, while 80-position receptacles accept SCSI drives.
The new Enhanced SCA-2 receptacle connectors, confirming to SFF8454, has design enhancements to improve impedance and reduce cross talk, allowing to operate at speeds of up to 8G Fibre-Channel applications.