Seagate ST3300656FC, ST3146356FC, ST3450856FC manual Prefetch operation

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If the number of write data logical blocks exceed the size of the segment being written into, when the end of the segment is reached, the data is written into the beginning of the same cache segment, overwriting the data that was written there at the beginning of the operation; however, the drive does not overwrite data that has not yet been written to the medium.

If write caching is enabled (WCE=1), then the drive may return Good status on a write command after the data has been transferred into the cache, but before the data has been written to the medium. If an error occurs while writing the data to the medium, and Good status has already been returned, a deferred error will be gen- erated.

The Synchronize Cache command may be used to force the drive to write all cached write data to the medium. Upon completion of a Synchronize Cache command, all data received from previous write commands will have been written to the medium.

Table 18 shows the mode default settings for the drive.

4.5.2Prefetch operation

If the Prefetch feature is enabled, data in contiguous logical blocks on the disc immediately beyond that which was requested by a Read command are retrieved and stored in the buffer for immediate transfer from the buffer to the host on subsequent Read commands that request those logical blocks (this is true even if cache operation is disabled). Though the prefetch operation uses the buffer as a cache, finding the requested data in the buffer is a prefetch hit, not a cache operation hit.

To enable Prefetch, use Mode Select page 08h, byte 12, bit 5 (Disable Read Ahead - DRA bit). DRA bit = 0 enables prefetch.

The drive does not use the Max Prefetch field (bytes 8 and 9) or the Prefetch Ceiling field (bytes 10 and 11).

When prefetch (read look-ahead) is enabled (enabled by DRA = 0), the drive enables prefetch of contiguous blocks from the disc when it senses that a prefetch hit will likely occur. The drive disables prefetch when it decides that a prefetch hit is not likely to occur.

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

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Contents Cheetah 15K.6 FC ST3450856FC ST3300656FC ST3146356FCPage Contents Installation Defect and error managementInterface requirements Seagate Technology support services Cheetah 15K.6 FC Product Manual, Rev. a List of Figures Page Scope Cheetah 15K.6 FC Product Manual, Rev. a Electromagnetic compatibility Applicable standards and reference documentationStandards Electromagnetic susceptibilityEuropean Union Restriction of Hazardous Substances RoHS Reference documents Ncits TR-20Cheetah 15K.6 FC Product Manual, Rev. a General description Standard features Media descriptionReliability Factory-installed optionsPerformance Formatted capacitiesUser-installed accessories Seek performance characteristics Performance characteristicsInternal drive characteristics Access timeStart/stop time Format command execution time minutesGeneral performance characteristics Prefetch/multi-segmented cache controlCache operation Caching write dataPrefetch operation Recoverable 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 MillisecondsPredictive failures Reporting controlDetermining rate Thermal monitorDrive Self Test DST State of the drive prior to testingParameter Code Description DST failure definitionShort test Function Code 001b Invoking DSTShort and extended tests Extended test Function Code 010bShipping Product warrantyAbort Product repair and return informationCheetah 15K.6 FC Product Manual, Rev. a DC power requirements Physical/electrical specificationsAC power requirements DC power requirements for ST3450856FC model Gbit AmpsDC power requirements for ST3300656FC model Gbit Amps DC power requirements for ST3146356FC model Gbit AmpsConducted noise immunity General DC power requirement notesPower sequencing Current profilesTypical ST3450856FC current profiles Typical ST3300656FC current profiles Typical ST3146356FC current profiles Power dissipation ST3450856FCST3300656FC Environmental limits TemperatureST3146356FC Shock and vibration Relative humidityEffective altitude sea level ShockPackage size Packaged/product weight Drop height Recommended mounting Acoustics Air cleanlinessVibration Corrosive environmentRoHS compliance statement Mechanical specifications Mounting configuration dimensionsCheetah 15K.6 FC Product Manual, Rev. a Drive internal defects/errors Defect and error managementDrive error recovery procedures Page FC-AL system errors Background Media ScanMedia Pre-Scan Deferred Auto-ReallocationIdle Read After Write Cheetah 15K.6 FC Product Manual, Rev. a Drive orientation InstallationDrive ID/option selection CoolingDrive mounting Air flowGrounding Cheetah 15K.6 FC Product Manual, Rev. a Link services supported Type of frame FC-AL featuresFibre Channel link service frames Interface requirementsFibre Channel task management responses Fibre Channel task management functionsFC Scsi FCP response codes Function name Response code Fibre Channel port login NPort login Plogi payload BytesNPort Login Accept ACC payload Bytes Fibre Channel port login acceptFibre Channel Process Login Process Login Plri payloadProcess Login Accept ACC payload Bytes Fibre Channel Process Login AcceptFibre Channel fabric login Fabric Login Flogi payload BytesFibre Channel fabric accept login Fabric Login Accept ACC payload BytesFC-AL options supported Dual port supportFibre Channel Arbitrated Loop options Option SupportedScsi commands supported Supported commands Command code Command nameVerify error recovery page 07h Cheetah 15K.6 FC Product Manual, Rev. a Temperature page 0Dh Inquiry data Mode Sense dataCheetah 15K.6 FC inquiry data Bytes Data hex Page Mode Data Header 000000 Cheetah 15K.6 FC Product Manual, Rev. a Supported Feature or condition Miscellaneous operating features and conditionsMiscellaneous features Miscellaneous statusFC-AL physical interface Physical characteristicsPhysical description Electrical description Connector requirementsPin descriptions Pin Signal name Signal type FC-SCA pin descriptions Pin Signal name Signal typeFC-AL transmitters and receivers Power Fault LED OutActive LED Out Enable port bypass signalsMotor start controls Parallel Enclosure Services Interface ESI 11 SEL6 through SEL0 ID linesArbitrated loop physical address Alpa values SettingHex Dec TTL input characteristics Signal characteristicsDevice control codes FC Differential output LED driver signalsFC Differential input Receive eye diagram Eye diagram data values Link rate GHz Cheetah 15K.6 FC Product Manual, Rev. a Presales Support Seagate Technology support servicesInternet Technical SupportData Recovery Services Authorized Service Centers Warranty ServiceData Recovery Services Call Center Toll-free Direct dial Index NumericsFAN Flogi Plogi Page See also cooling
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ST3450856FC, ST3300656FC, ST3146356FC specifications

The Seagate ST3146356FC, ST3300656FC, and ST3450856FC are hard disk drives designed for enterprise storage solutions, showcasing Seagate’s commitment to performance, reliability, and advanced technology in the data storage sector. These drives cater primarily to the needs of data centers and businesses requiring robust data management capabilities.

The ST3146356FC is notable for its 146GB capacity, 3.5-inch form factor, and 10,000 RPM spindle speed. It employs Serial Attached SCSI (SAS) interface technology, which ensures high data transfer rates and reliable connectivity. This model is designed to handle a multitude of demanding applications, such as online transaction processing and enterprise resource planning, requiring fast access to data and minimized latency.

The ST3300656FC, with a capacity of 300GB, continues the trend of high performance set by its predecessor. This drive also features the 10,000 RPM spindle speed and SAS interface, providing enhanced data throughput and optimized performance for intensive workloads. The drive is built with advanced error recovery features that enhance data integrity and reliability, making it suitable for critical applications where data loss is unacceptable.

The ST3450856FC offers even greater capacity, with a robust 450GB storage option. Like the other models, it operates at 10,000 RPM and utilizes the SAS interface. This drive is designed for scalability, ensuring that it can meet the evolving storage demands of enterprises. It is also equipped with sophisticated technologies such as Seagate's Enhanced S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology), providing continual monitoring of the drive’s health and performance metrics.

All three models share key characteristics, including advanced thermal and power management technologies that help maintain optimal operating temperatures and reduce energy consumption. This is crucial in data center environments where maximizing efficiency is vital for operational cost management. Additionally, Seagate's commitment to low acoustic noise levels ensures quieter operation, which is beneficial in environments where sound levels must be controlled.

In summary, the Seagate ST3146356FC, ST3300656FC, and ST3450856FC drives are engineered for enterprise environments demanding high reliability, speed, and capacity. Their advanced technologies, including SAS interface and enhanced error management systems, make these drives ideal for critical applications in data-intensive sectors. With reinforced durability, effectiveness in managing large volumes of data, and a focus on energy efficiency, these drives symbolize the pinnacle of Seagate's storage innovations for enterprise solutions.
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