Performance characteristics, Access time | Seagate ST31000640SSIM

4.0Performance characteristics

This section provides detailed information concerning performance-related characteristics and features of Barracuda ES.2 SAS drives.

4.1Internal drive characteristics

	ST31000640SS	ST3750630SS	ST3500620SS
Drive capacity	1,000	750	500	Gbytes (formatted, rounded value)*
Read/write data heads	8	6	4
Tracks per inch	150,000	150,000	150,000	TPI
Peak bits per inch	1,090k	1,090k	1,090k	BPI
Areal Density	164	164	164	Gbits/inch2
Internal data rate	1,287	1,287	1,287	Mb/s max (variable with zone)
Sustained data rate	116	116	116	MB/s max (variable with zone)*
Disk rotation speed	7,200	7,200	7,200	RPM
Avg rotational latency	4.16	4.16	4.16	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 performance

See Section 9.4.1, "SAS physical interface" on page 55 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	7.4	8.5
Single track	Typical	0.4	1.0
Full stroke	Typical	14.3	15.4

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.

Barracuda ES.2 SAS Product Manual, Rev. G

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Seagate ST31000640SSIM manual Performance characteristics, Internal drive characteristics, Seek performance, Access time

Contents

ST31000640SS ST3750630SS ST3500620SS Barracuda ES.2 SASPage Reliability specifications Performance characteristicsPhysical/electrical specifications General description Interface requirements Defect and error managementInstallation Seagate Technology Support Services Barracuda ES.2 SAS Product Manual, Rev Scope Barracuda ES.2 SAS Product Manual, Rev. G Standards Standards, compliance and reference documentsElectromagnetic compatibility Electromagnetic susceptibility Compliance Reference documents Barracuda ES.2 SAS Product Manual, Rev. G Barracuda ES.2 drive illustration General description Media description Standard featuresPerformance Reliability Programmable drive capacity Factory-installed optionsFormatted capacities Barracuda ES.2 SAS Product Manual, Rev. G Internal drive characteristics Performance characteristicsAccess time Seek performance Start/stop time Format command execution time minutesGeneral performance characteristics Caching write data Prefetch/multi-segmented cache controlCache operation Prefetch operation Error rates Reliability specificationsRecoverable Errors Unrecoverable Errors Seek errors Reliability and serviceInterface errors Preventive maintenance Controlling S.M.A.R.T 4 S.M.A.R.TPerformance impact Reporting control Thermal monitor Temperature Log Page 0DhPredictive failures DST failure definition State of the drive prior to testingImplementation Invoking DST Short test Function Code 001b Product warrantyExtended test Function Code 010b Log page entries Product repair and return information Shipping Barracuda ES.2 SAS Product Manual, Rev. G AC power requirements Physical/electrical specificationsDC power requirements ST31000640SS DC power requirements ST3500620SS DC power requirements ST3750630SS DC power requirements Power sequencing General DC power requirement notesConducted noise immunity Current profiles Typical ST31000640SS drive +5V and +12V current profiles Typical ST3500620SS drive +5V and +12V current profiles Power dissipation Barracuda ES.2 SAS Product Manual, Rev. G Environmental limits Temperature a. Operating Effective altitude sea level a. Operating Relative humidityShock and vibration Shock Package size Packaged/product weight Drop height Vibration a. Operating-normal Air cleanlinessAcoustics Corrosive environment See Section Barracuda ES.2 SAS Product Manual, Rev. G Physical dimensions Mechanical specifications Drive error recovery procedures Defect and error managementDrive internal defects/errors 108.29 Media Pre-Scan SAS system errorsBackground Media Scan Idle Read After Write Deferred Auto-Reallocation Drive orientation Installation Air flow Cooling Grounding Drive mounting Barracuda ES.2 SAS Product Manual, Rev. G Interface requirements SAS features Dual port support Command name Command code Supported Scsi commands supportedCommands supported by Barracuda ES.2 SAS family drives Commands supported by Barracuda ES.2 SAS family drives Commands supported by Barracuda ES.2 SAS family drives Commands supported by Barracuda ES.2 SAS family drives Barracuda ES.2 SAS inquiry data Bytes Data hex Mode Sense dataInquiry data Page Mode Pages 2.1 ST31000640SS Mode Sense data 2.2 ST3750630SS Mode Sense data 2.3 ST3500620SS Mode Sense data Miscellaneous features Miscellaneous operating features and conditionsSupported Feature or condition Miscellaneous status SAS physical interface Datum B Connector requirements Physical characteristics Electrical description Pin Signal name Signal typePin descriptions SAS pin descriptions Power Signal characteristicsSAS transmitters and receivers Ready LED Out Differential signals LED drive signalGeneral interface characteristics Eye masks Eye masks overview Jitter tolerance masks Receive eye maskAbsolute amplitude Normalized time in UI Sinusoidal Peak-toJitter Frequency in kHz Signal characteristica Units Gbps Transmitter signal characteristics Signal characteristic Units Gbps Receiver signal characteristicsMaximum allowable jitter Gbps m, n Deterministic jitterq Receiver jitter tolerance Impedance specificationsCompliant jitter test pattern Cjtpat Impedance requirements Sheet 1 Electrical TxRx connections Transmitter characteristicsImpedance requirements Sheet 2 = -5,437dB Shows the zero-length test load Receiver characteristics Barracuda ES.2 SAS Product Manual, Rev. G