Serial Attached SCSI or SAS, is an interface for serial data transfer, the successor to SCSI (Small Computer System Interface) parallel, but still uses SCSI commands for interacting with SAS devices. It increases speed and allows connection and disconnection quickly. The first version appeared in late 2003: SAS 300, getting a bandwidth of 3 Gbit/s, which increased the speed slightlyits predecessor, the Ultra SCSI 320 MB/s (2.560 Gbit/s). The next evolution, SAS 600, achieves a speed of up to 6 Gbit/s, while expected to reach a speed of about 12 Gbit/s circa 2010.

InfiniBand is a bus of high speed serial communications, designed for both internal and external connections. Infiniband uses a bidirectional serial bus so that avoids the typical problems associated with parallel buses over long distances (in this context, a room or building). Despite being a serial connection, it is very fast, giving a gross rate of 2.5 Gigabits per second (Gbps) in each directionper link.

The SFF connectors are distinguished by their smaller size, they are ideal for saving space. The SFF connectors also increase port density cards, switches etc ..