Seagate ST3450856SS manual Performance characteristics, Internal drive characteristics, Seek time

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4.0Performance characteristics

This section provides detailed information concerning performance-related characteristics and features of Cheetah drives.

4.1Internal drive characteristics

	ST3450856SS	ST3300656SS	ST3146356SS	Gbytes (formatted, rounded off value),*
Drive capacity	450	300	146	Gbytes (formatted, rounded off value),*
Read/write data heads	8	6	3
Tracks per inch	150,000	150,000	150,000	TPI
Peak bits per inch	1,100	1,100	1,100	KBPI
Areal Density	165	165	165	Gbits/inch2
Internal data rate	1.95	1.95	1.95	Gbits/sec (max)
disk rotation speed	15k	15k	15k	RPM
Avg rotational latency	2.0	2.0	2.0	msec

*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment and formatting.

**Rounded off value.

4.2Seek time

See Section 9.4.1, "SAS physical interface" on page 59 and the SAS Interface Manual (part number 100293071) for additional timing details.

4.2.1Access time

Not Including controller overhead1, 2 (msec)

		Read	Write
Average	Typical	3.4	3.9
Single track	Typical	0.20	0.44
Full stroke	Typical	6.43	7.12

1.Typical access times are measured under nominal conditions of temperature, voltage, and horizontal orientation as measured on a representative sample of drives.

2.Access to data = access time + latency time.

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

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Contents ST3450856SS ST3300656SS ST3146356SS Cheetah 15K.6 SASPage Contents Installation Defect and error managementSeagate Technology support services Interface requirementsCheetah 15K.6 SAS disk drive List of FiguresCheetah 15K.6 SAS Product Manual, Rev. a Cheetah 15K.6 SAS disk drive ScopeCheetah 15K.6 SAS Product Manual, Rev. a Standards Standards, compliance and reference documentsElectromagnetic compatibility Electromagnetic susceptibilityEuropean Union Restriction of Hazardous Substances RoHS ComplianceReference documents Cheetah 15K.6 SAS Product Manual, Rev. a General description Performance Standard featuresMedia description Options factory installed Factory-installed accessoriesReliability Formatted capacitiesCheetah 15K.6 SAS Product Manual, Rev. a Internal drive characteristics Performance characteristicsAccess time Seek timeStart/stop time Format command execution time minutesGeneral performance characteristics Cache operation Prefetch/multi-segmented cache controlPrefetch operation Caching write dataError rates Reliability specificationsRecoverable Errors Unrecoverable ErrorsSeek errors Reliability and serviceInterface errors Preventive maintenanceControlling S.M.A.R.T 4 S.M.A.R.TPerformance impact MillisecondsDetermining rate Reporting controlPredictive failures Thermal monitorPrimary Temperature Temperature Log Page 0DhReference Temperature Parameter Code DescriptionInvoking DST State of the drive prior to testingShort and extended tests Short test Function Code 001bAbort Product warrantyShipping Product repair and return informationCheetah 15K.6 SAS Product Manual, Rev. a AC power requirements Physical/electrical specificationsDC power requirements ST3450856SS DC power requirementsST3146356SS DC power requirements ST3300656SS DC power requirementsST3300656SS Gbit mode Amps ST3146356SS Gbit mode AmpsPower sequencing General DC power requirement notesConducted noise immunity Current profilesTypical ST3450856SS current profiles Typical ST3300656SS current profiles Typical ST3146356SS current profiles ST3450856SS in 3 Gbit operation Power dissipationST3300656SS in 3 Gbit operation ST3300656SS CURRENT/POWER vs Throughput SAS 3.0GBRandom 8 Block Reads ST3146356SS CURRENT/POWER vs Throughput SAS 3.0GBST3146356SS in 3 Gbit operation Environmental limits TemperatureEffective altitude sea level Relative humidityShock and vibration ShockRecommended mounting Package size Packaged/product weight Drop heightVibration Air cleanlinessAcoustics Corrosive environmentMechanical specifications Physical dimensions Cheetah 15K.6 SAS Product Manual, Rev. a Drive error recovery procedures Defect and error managementDrive internal defects/errors 51.87 Media Pre-Scan SAS system errorsBackground Media Scan Idle Read After Write Deferred Auto-ReallocationDrive orientation InstallationAir flow CoolingGrounding Drive mountingCheetah 15K.6 SAS Product Manual, Rev. a Interface requirements SAS featuresDual port support Command name Command code Supported Scsi commands supportedCommands 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 Commands supported by Cheetah 15K.6 SAS family drives Bytes Data hex Mode Sense dataInquiry data Page Mode Pages 2.1 ST3450856SS Mode Sense data2.2 ST3300656SS Mode Sense data 2.3 ST3146356SS Mode Sense data Miscellaneous features Miscellaneous operating features and conditionsSupported Feature or condition Miscellaneous statusSAS physical interface Datum B Connector requirements Physical characteristicsElectrical description Pin Signal name Signal typePin descriptions SAS pin descriptionsPower Signal characteristicsSAS transmitters and receivers Ready LED OutDifferential signals LED drive signalGeneral interface characteristics Eye masks Eye masks overviewJitter tolerance masks Receive eye maskAbsolute amplitude Normalized time in UISinusoidal Peak-toJitter Frequency in kHzSignal characteristica Units Gbps Transmitter signal characteristicsSignal characteristic Units Gbps Receiver signal characteristicsMaximum allowable jitter Gbps m, n Deterministic jitterqReceiver jitter tolerance Impedance specificationsCompliant jitter test pattern Cjtpat Impedance requirements Sheet 1Electrical TxRx connections Transmitter characteristicsImpedance requirements Sheet 2 = -5,437dB Shows the zero-length test load Receiver characteristics Cheetah 15K.6 SAS Product Manual, Rev. a Internet Seagate Technology support servicesPresales Support Technical SupportData Recovery Services Call Center Toll-free Direct dial Warranty ServiceData Recovery Services Authorized Service Centers Numerics IndexPage SAS See also cooling