Seagate ST3146854LC 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 15K.6 drives.

4.1Internal drive characteristics

	ST3450856SS	ST3300656SS	ST3146356SS
	ST3450056SS	ST3300056SS	ST3146756SS
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.

4.2Seek time

See Section 9.4.1, "SAS physical interface" on page 62 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. B

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Contents ST3450856SS ST3300656SSST3146356SS Page Contents Interface requirements Defect and error managementInstallation Seagate Technology support servicesModel Number Full Disk Encryption FDE ScopeCheetah 15K.6 SAS Product Manual, Rev. B Electromagnetic susceptibility Standards, compliance and reference documentsStandards Electromagnetic compatibilityEuropean Union Restriction of Hazardous Substances RoHS ComplianceReference documents Cheetah 15K.6 SAS Product Manual, Rev. B General description Standard features Media descriptionPerformance Programmable drive capacity Factory-installed optionsReliability Formatted capacitiesCheetah 15K.6 SAS Product Manual, Rev. B Seek time Performance characteristicsInternal drive characteristics Access time176 144 100 Format command execution time minutesGeneral performance characteristics Start/stop timeCache operation Prefetch/multi-segmented cache controlPrefetch operation Caching write dataUnrecoverable Errors Reliability specificationsError rates Recoverable ErrorsPreventive maintenance Reliability and serviceSeek errors Interface errorsMilliseconds 4 S.M.A.R.TControlling S.M.A.R.T Performance impactThermal monitor Reporting controlDetermining rate Predictive failuresDST failure definition Temperature Log Page 0Dh Parameter Code DescriptionState of the drive prior to testing Drive Self Test DSTExtended test Function Code 010b Invoking DSTShort and extended tests Short test Function Code 001bProduct repair and return information Product warrantyAbort ShippingCheetah 15K.6 SAS Product Manual, Rev. B ST3450856SS DC power requirements Physical/electrical specificationsAC power requirements DC power requirementsST3300656SS Gbit mode Amps ST3450056SS FDE DC power requirementsST3300656SS DC power requirements ST3450056SS FDE Gbit mode AmpsST3146356SS Gbit mode Amps ST3300056SS FDE DC power requirementsST3146356SS DC power requirements ST3300056SS FDE Gbit mode AmpsST3146756SS FDE Gbit mode Amps ST3146756SS FDE DC power requirementsPower sequencing Conducted noise immunityCurrent profiles Typical 450GB current profiles Typical 146GB current profiles ST3450856SS model Power dissipationST3450056SS FDE model ST3300656SS model ST3300056SS FDE model ST3146356SS model ST3146756SS FDE model in 3 Gbit operation Environmental limits TemperatureShock Relative humidityEffective altitude sea level Shock and vibrationRecommended mounting Package size Packaged/product weight Drop heightCorrosive environment Air cleanlinessVibration AcousticsMechanical specifications Physical dimensions Cheetah 15K.6 SAS Product Manual, Rev. B Defect and error management Drive internal defects/errorsDrive error recovery procedures 51.87 SAS system errors Background Media ScanMedia Pre-Scan Idle Read After Write Deferred Auto-ReallocationInstallation Drive orientationCooling Air flow Grounding Drive mountingCheetah 15K.6 SAS Product Manual, Rev. B Interface requirements SAS featuresDual 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 Bytes Data hex Inquiry dataMode Sense data Mode Pages 2.1 ST3450856SS/ST3450056SS Mode Sense data2.2 ST3300656SS/ST3300056SS Mode Sense data 2.3 ST3146356SS/ST3146756SS Mode Sense data SAS physical interface Miscellaneous operating features and conditionsMiscellaneous features Miscellaneous statusPhysical interface Datum B Connector requirements Physical characteristicsSAS pin descriptions Pin Signal name Signal typeElectrical description Pin descriptionsReady LED Out Signal characteristicsPower SAS transmitters and receiversEye masks Eye masks overview LED drive signalDifferential signals General interface characteristicsNormalized time in UI Receive eye maskJitter tolerance masks Absolute amplitudeFrequency in kHz Peak-toSinusoidal JitterSignal characteristica Units Gbps Transmitter signal characteristicsReceiver signal characteristics Signal characteristic Units GbpsMaximum allowable jitter Impedance requirements Sheet 1 Impedance specificationsReceiver jitter tolerance Compliant jitter test pattern CjtpatTransmitter characteristics Impedance requirements Sheet 2Electrical TxRx connections = -5,437dB Shows the zero-length test load Receiver characteristics Cheetah 15K.6 SAS Product Manual, Rev. B Technical Support Seagate Technology support servicesInternet Presales SupportWarranty Service Data Recovery Services Authorized Service CentersData Recovery Services Call Center Toll-free Direct dial Numerics IndexIraw SAS See also cooling