Seagate ST336807FC manual Start/stop time, Prefetch/multi-segmented cache control, Cache operation

Page 25

Flaw reallocation performance impact (for flaws reallocated at format time

Negligible

using the spare sectors per sparing zone reallocation scheme.)

 

Overhead time for head switch in sequential mode

0.8 msec

 

Overhead time for one track cylinder switch in sequential mode

1.2 msec (typical)

Average rotational latency

3.0 msec

*Assumes no errors and no relocated logical blocks. Rate measured from the start of the first logical block transfer to or from the host.

Notes for Section 4.2.

[1]Execution time measured from receipt of the last byte of the Command Descriptor Block (CDB) to the request for a Status Byte Transfer to the Initiator (excluding connect/disconnect).

[2]Typical access times are measured under nominal conditions of temperature, voltage, and horizontal ori- entation as measured on a representative sample of drives.

[3]Assumes system ability to support the rates listed and no cable loss.

[4]Access to data = access time + latency time.

4.3Start/stop time

If the Motor Start option is disabled, the drive becomes ready within 25 seconds after DC power is applied. If a recoverable error condition is detected during the start sequence, the drive executes a recovery procedure and the time to become ready may exceed 25 seconds. Stop time is less than 30 seconds (maximum) from removal of DC power.

If the Motor Start option is enabled, the internal controller accepts the commands listed in the Fibre Channel Interface Manual less than 3 seconds after DC power has been applied. After the Motor Start command has been received, the drive becomes ready for normal operations within 25 seconds (excluding the error recovery procedure). The Motor Start command can also be used to command the drive to stop the spindle.

There is no power control switch on the drive.

4.4Prefetch/multi-segmented cache control

The drive provides a prefetch (read look-ahead) and multi-segmented cache control algorithms that in many cases can enhance system performance. Cache refers to the drive buffer storage space when it is used in cache operations. To select this feature, the host sends the Mode Select command with the proper values in the applicable bytes in page 08h. Prefetch and cache operations are independent features from the standpoint that each is enabled and disabled independently using the Mode Select command; however, in actual opera- tion, the prefetch feature overlaps cache operation somewhat as described in sections 4.5.1 and 4.5.2.

All default cache and prefetch mode parameter values (Mode Page 08h) for standard OEM versions of this drive family are given in Table 25.

4.5Cache operation

Note. Refer to the Fibre Channel Interface Manual for more detail concerning the cache bits.

Of the 8,192 kbytes physical buffer space in the drive, 6,991 kbytes can be used as a cache. The buffer can be divided into logical segments (using Mode Select Page 08h, byte 13) from which data is read and to which data is written.

Cheetah 10K.7 36GB FC Product Manual, Rev. A

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Contents Cheetah 10K.7 FC Page Cheetah 10K.7 FC Page Rev. a 05/04/05 All. Initial release Revision status summary sheetRevision Date Sheets Affected Page Contents Defect and error management Physical/electrical specificationsInstallation Interface requirementsSeagate Technology support services Viii Cheetah 10K.7 36GB FC Product Manual, Rev. a Cheetah 10K.7 FC family disc drive List of FiguresCheetah 10K.7 36GB FC Product Manual, Rev. a Cheetah 10K.7 FC family disc drive ScopeCheetah 10K.7 36GB FC Product Manual, Rev. a Standards Applicable standards and reference documentationElectromagnetic compatibility Electromagnetic susceptibilityEuropean Union Restriction of Hazardous Substances RoHS Electromagnetic complianceFibre Channel Interface Manual Reference documentsCheetah 10K.7 36GB FC Product Manual, Rev. a General description Media description Standard featuresReliability PerformanceFormatted capacities Programmable drive capacityFactory-installed options Factory-installed accessoriesUser-installed accessories Internal drive characteristics Performance characteristicsST336807FC Access time Seek performance characteristicsFormat command execution time in minutes Generalized performance characteristicsPrefetch/multi-segmented cache control Start/stop timeCache operation Caching write data Prefetch operation Cheetah 10K.7 36GB FC Product Manual, Rev. a Error rates Reliability specificationsRecoverable Errors Reliability and service 4 S.M.A.R.T Hot plugging the driveControlling S.M.A.R.T Milliseconds Performance impactReporting control Determining rateParameter Code Description Temperature Log page 0DhDrive Self Test DST DST Failure Definition State of the drive prior to testingImplementation Invoking DSTShort test Function Code 001b Product warrantyExtended test Function Code 010b Log page entriesProduct repair and return information ShippingAC power requirements Physical/electrical specificationsDC power requirements ST336807FC DC power requirementsPower sequencing General DC power requirement notesConducted noise immunity Typical ST336807FC drive, 2 Gbit, +5V current profile Typical ST336807FC drive, 2 Gbit, +12V current profileST336807FC Power dissipationEnvironmental limits TemperatureRelative humidity Effective altitude sea levelShock and vibration Package size Packaged/product weight Drop heightShock Recommended mounting Vibration Air cleanlinessCorrosive environment Acoustics Mechanical specificationsMounting configuration dimensions Drive internal defects/errors Defect and error managementDrive error recovery procedures 77.7 Background Media Scan FC-AL system errorsMedia Pre-Scan Cheetah 10K.7 36GB FC Product Manual, Rev. a Drive ID/option selection InstallationPhysical interface Drive Front LED connectionsDrive orientation 1 J6 connector requirementsCooling Grounding Drive mountingFibre Channel link service frames FC-AL featuresLink services supported Type of frame Link serviceFibre Channel Scsi FCP task management functions Fibre Channel task management functionsFibre Channel task management responses FC Scsi FCP response codesNPort login Plogi payload Fibre Channel port loginBytes NPort Login Accept ACC payload Fibre Channel port login acceptFibre Channel Process Login Process Login Plri payloadProcess Login Accept ACC payload Fibre Channel Process Login AcceptFibre Channel fabric login Fabric Login Flogi payloadFabric Login Accept ACC payload Fibre Channel fabric accept loginFibre Channel Arbitrated Loop options Dual port supportFC-AL options supported Option SupportedSupported commands Scsi commands supportedCommand code Supported Command name Supported commands Supported commands Supported commands Supported commands Inquiry data Mode Sense dataCheetah 10K.7 FC inquiry data Bytes Data hexPage DEF CHG Miscellaneous features Miscellaneous operating features and conditionsSupported Feature or condition Miscellaneous statusFC-AL physical interface Physical characteristicsPhysical description Part description Positions Part number Features Connector requirementsElectrical description J6 connector dimensionsPin descriptions Pin Signal name Signal typeFC-SCA pin descriptions Fault LED Out PowerFC-AL transmitters and receivers Normal command activity LED status Enable port bypass signalsActive LED Out Active LED Out conditionsParallel Enclosure Services Interface ESI Motor start control signalsMotor start controls 11 SEL6 through SEL0 ID linesArbitrated loop physical address Alpa values SettingHex Dec Signal characteristics LED drive signal LED driver signalsDifferential Pecl output characteristics Differential Pecl input characteristicsLink rate GHz Eye diagram data valuesCheetah 10K.7 36GB FC Product Manual, Rev. a Internet MySeagate Reseller.seagate.com Seagate Technology support servicesPresales Support Technical SupportData Recovery Services Authorized Service Centers Warranty ServiceData Recovery Services Call center Presales and Technical Support Warranty Service FAX services-All Europe toll callToll-free support numbers Asia/Pacific support services Publication feedback survey Cheetah 10K.7 36GB FC Product Manual, Rev. a Numerics IndexFAN Flogi PBC Page See also cooling
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