Dual port support | Seagate ST3146356SS, ST3300656SS, ST3450856SS

9.2Dual port support

Cheetah 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 Cheetah 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.

48	Cheetah 15K.6 SAS Product Manual, Rev. A

Image 54

Seagate ST3146356SS, ST3300656SS, ST3450856SS manual Dual port support

Contents

Cheetah 15K.6 SAS ST3450856SS ST3300656SS ST3146356SSPage Contents Seagate Technology support services Defect and error managementInstallation Interface requirements List of Figures Cheetah 15K.6 SAS disk drive Cheetah 15K.6 SAS Product Manual, Rev. a Scope Cheetah 15K.6 SAS disk drive Cheetah 15K.6 SAS Product Manual, Rev. a Electromagnetic compatibility Standards, compliance and reference documentsStandards Electromagnetic susceptibility Compliance European Union Restriction of Hazardous Substances RoHS Reference documents Cheetah 15K.6 SAS Product Manual, Rev. a General description Standard features Media descriptionPerformance Reliability Factory-installed accessoriesOptions factory installed Formatted capacities Cheetah 15K.6 SAS Product Manual, Rev. a Access time Performance characteristicsInternal drive characteristics Seek time Format command execution time minutes General performance characteristicsStart/stop time Prefetch/multi-segmented cache control Cache operation Caching write data Prefetch operation Recoverable Errors Reliability specificationsError rates Unrecoverable Errors Interface errors Reliability and serviceSeek errors Preventive maintenance Performance impact 4 S.M.A.R.TControlling S.M.A.R.T Milliseconds Predictive failures Reporting controlDetermining rate Thermal monitor Reference Temperature Temperature Log Page 0DhPrimary Temperature Parameter Code Description Short and extended tests State of the drive prior to testingInvoking DST Short test Function Code 001b Shipping Product warrantyAbort Product repair and return information Cheetah 15K.6 SAS Product Manual, Rev. a DC power requirements Physical/electrical specificationsAC power requirements ST3450856SS DC power requirements ST3300656SS Gbit mode Amps ST3300656SS DC power requirementsST3146356SS DC power requirements ST3146356SS Gbit mode Amps Conducted noise immunity General DC power requirement notesPower sequencing Current profiles Typical ST3450856SS current profiles Typical ST3300656SS current profiles Typical ST3146356SS current profiles Power dissipation ST3450856SS in 3 Gbit operation ST3300656SS CURRENT/POWER vs Throughput SAS 3.0GB ST3300656SS in 3 Gbit operation ST3146356SS CURRENT/POWER vs Throughput SAS 3.0GB ST3146356SS in 3 Gbit operationRandom 8 Block Reads Temperature Environmental limits Shock and vibration Relative humidityEffective altitude sea level Shock Package size Packaged/product weight Drop height Recommended mounting Acoustics Air cleanlinessVibration Corrosive environment Mechanical specifications Physical dimensions Cheetah 15K.6 SAS Product Manual, Rev. a Defect and error management Drive internal defects/errorsDrive error recovery procedures 51.87 SAS system errors Background Media ScanMedia Pre-Scan Deferred Auto-Reallocation Idle Read After Write Installation Drive orientation Cooling Air flow Drive mounting Grounding Cheetah 15K.6 SAS Product Manual, Rev. a SAS features Interface requirements Dual port support Scsi commands supported Commands supported by Cheetah 15K.6 SAS family drivesCommand name Command code Supported Commands supported by Cheetah 15K.6 SAS family drives Commands supported by Cheetah 15K.6 SAS family drives Commands supported by Cheetah 15K.6 SAS family drives Mode Sense data Inquiry dataBytes Data hex Page 2.1 ST3450856SS Mode Sense data Mode Pages 2.2 ST3300656SS Mode Sense data 2.3 ST3146356SS Mode Sense data Supported Feature or condition Miscellaneous operating features and conditionsMiscellaneous features Miscellaneous status SAS physical interface Datum B Physical characteristics Connector requirements Pin descriptions Pin Signal name Signal typeElectrical description SAS pin descriptions SAS transmitters and receivers Signal characteristicsPower Ready LED Out General interface characteristics LED drive signalDifferential signals Eye masks Eye masks overview Absolute amplitude Receive eye maskJitter tolerance masks Normalized time in UI Jitter Peak-toSinusoidal Frequency in kHz Transmitter signal characteristics Signal characteristica Units Gbps Maximum allowable jitter Receiver signal characteristicsSignal characteristic Units Gbps Gbps m, n Deterministic jitterq Compliant jitter test pattern Cjtpat Impedance specificationsReceiver jitter tolerance Impedance requirements Sheet 1 Transmitter characteristics Impedance requirements Sheet 2Electrical TxRx connections = -5,437dB Shows the zero-length test load Receiver characteristics Cheetah 15K.6 SAS Product Manual, Rev. a Presales Support Seagate Technology support servicesInternet Technical Support Warranty Service Data Recovery Services Authorized Service CentersData Recovery Services Call Center Toll-free Direct dial Index NumericsPage SAS See also cooling