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Each single-phy link (also called a
narrow port
) supports a maximum bandwidth of 1200 MB/s (12.0 Gb/s) per
direction, with a total bandwidth of 2400 MB/s full duplex in both directions.
A wide SAS port consists of more than one SAS phy (an 8-phy SAS port is also possible). A wide SAS port transmits
and receives data by using the same SAS address when connected to another SAS wide port. In other words, the
port is created dynamically when the connection is made. The following figure shows both a narrow SAS port and
a wide SAS port
Figure 5 Narrow and Wide SAS Ports
The A54812-SW switch has 48 phys, numbered 0 through 47. Each of the 12 SAS connectors on the switch case
(numbered 0 through 11 in this document) contains four phys, making them wide ports.
During normal operation, the SAS connectors on the switch are cabled to SAS connectors on initiator devices or
target devices. This connection creates a wide SAS port through which data is transmitted and received.
