Seagate ST973402SS, ST9146802SS manual Dual port support

9.2Dual port support

Savvio SAS drives have two independent ports. These ports may be connected in the same or different SCSI domains. Each drive port has a unique SAS address.

The two ports run at the same link rate. The first port to successfully complete speed negotiation sets the link rate support by both ports. When the second port participates in speed negotiation, it indicates the only sup- ported speed is the speed selected by the first port. If the first port to complete speed negotiation looses sync before the second port completes speed negotiation, both ports revert back to the power on condition of allow- ing either link rate (1.5 or 3.0 Gbits/sec).

Subject to buffer availability, the Savvio drives support:

•Concurrent port transfers—The drive supports receiving COMMAND, TASK management transfers on both ports at the same time.

•Full duplex—The drive supports sending XFER_RDY, DATA and RESPONSE transfers while receiving frames on both ports.

46 Savvio 10K.2 SAS Product Manual, Rev. B