Seagate ST973452SS manual Performance characteristics, Internal drive characteristics, Access time

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5.0Performance characteristics

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

5.1Internal drive characteristics

	ST9146852SS	ST973452SS
	ST9146752SS	ST973352SS
	ST9146652SS	ST973252SS
Drive capacity	146.8	73.4	Gbytes (formatted, rounded off value)
Read/write data heads	4	2
Tracks per surface (total)	60,436	60,436	Tracks (user accessible including spare tracks)
Tracks per inch	180,000	180,000	kTPI (average)
Peak bits per inch	1,317	1,317	kBPI
Areal density	237.1	237.1	Gbit/in2
Internal data rate	1,936 - 1,409	1,936 - 1,409	Mbits/sec (variable with zone)
Disk rotation speed	15k	15k	rpm
Avg rotational latency	2.0	2.0	msec

5.2Seek performance characteristics

See Section 12.4.1, "SAS physical interface" on page 57 and the SAS Interface Manual (part number 100293071) for additional timing details.

5.2.1Access time

		Including controller overhead1, 2		Not including controller overhead1, 2
		(msec)		(msec)
		Read	Write	Read	Write
Average	Typical3,4	3.1	3.5	2.9	3.3
Single track	Typical3,4	0.2	0.42	0.2	0.42
Full stroke	Typical3,4	5.05	5.4	4.85	5.2

1.Execution time measured from receipt of the Command to the Response.

2.Assumes no errors and no sector has been relocated.

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

4.Access time = controller overhead + average seek time and applies to all data transfer commands. Access to data = access time + latency time.

10	Savvio 15K.2 SAS Product Manual, Rev. E

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Contents Standard Models Self-Encrypting Drive Models ST9146852SSST9146752SS ST973452SSST973352SSST9146652SS ST973252SS SED Fips 140-2 ModelsPage Contents About Fips About self-encrypting drives Defect and error managementInstallation Interface requirementsPage Savvio 15K.2 SAS Product Manual, Rev. E List of Figures Page Seagate Technology support services Seagate Online Support and ServicesScope Electromagnetic compatibility Applicable standards and reference documentationStandards Electromagnetic susceptibilityAustralian C-Tick Electromagnetic complianceElectromagnetic compliance for the European Union Korean MICReference documents European Union Restriction of Hazardous Substances RoHSGeneral description Standard features Media descriptionPerformance ReliabilityFormatted capacities Programmable drive capacity OptionsSeek performance characteristics Performance characteristicsInternal drive characteristics Access timeFormat command execution time General performance characteristicsStart/stop time Prefetch/multi-segmented cache control Cache operationCaching write data Prefetch operationRecoverable Errors Reliability specificationsError rates Unrecoverable ErrorsInterface errors Reliability and serviceSeek errors Preventive maintenancePerformance impact 4 S.M.A.R.TControlling S.M.A.R.T Reporting controlTemperature Log Page 0Dh Parameter Code Description Predictive failuresThermal monitor DST failure definition State of the drive prior to testingDrive Self Test DST ImplementationExtended test Function Code 010b Short and extended testsShort test Function Code 001b Log page entriesProduct warranty ShippingProduct repair and return information Physical/electrical specifications AC power requirementsDC power requirements 146GB models DC power requirements Gbit mode Amps73GB models DC power requirements General DC power requirement notes Power sequencingConducted noise immunity Current profiles Current profile for 146GB modelsCurrent profile for 73GB models Power dissipation 146GB models in 6.0 Gbit operation146GB models in 3.0 Gbit operation 73GB models in 6.0 Gbit operation 73GB models in 3.0 Gbit operationTemperature a. Operating Environmental limitsRelative humidity Effective altitude sea level a. Operating Shock and vibrationShock Recommended mounting Air cleanliness Vibration a. Operating-normalCorrosive environment Acoustics Mechanical specifications DimensionsAbout Fips PurposeLevel 2 security About self-encrypting drives Controlled accessAdmin SP Data encryptionDrive locking Default passwordRandom number generator RNG Data bandsSupported commands Authenticated firmware downloadPower requirements Cryptographic eraseDefect and error management Drive internal defects/errorsDrive error recovery procedures SAS system errors Background Media Scan Media Pre-ScanDeferred Auto-Reallocation Idle Read After Write Installation Drive orientationCooling Air flowDrive mounting GroundingSAS features Interface requirementsDual port support Scsi commands supported Supported commandsSupported commands Supported commands Supported commands Mode Sense data Inquiry dataSavvio inquiry data Page Mode Data Header 00 00 05 12 8B 00 10 Miscellaneous operating features and conditions Miscellaneous featuresMiscellaneous status SAS physical interface Datum B Section C C Section a a Electrical description Physical characteristicsConnector requirements Pin descriptionsSAS pin descriptions SAS transmitters and receiversSignal characteristics SAS-2 Specification compliance General interface characteristicsAdditional information Savvio 15K.2 SAS Product Manual, Rev. E Index NumericsIraw Msid Mtbf See also cooling