IBM C4B 4.51 Brick On Sled carrier 128-pin HPC Cylinder to Cylinder Skew, Track to Track Skew

Page 46

U S E R RESPONSIBLE F O R V E R I F Y I N G VERSION A N D COMPLETENESS

O E M F U N C T I O N A L S P E C I F I C A T I O N U L T R A S T A R X P ( D F H C ) SSA M O D E L S 1.12/2.25 G B - 1.0" H I G H

The full benefit of out of order transfers in only achieved if O O T I is also set. Read data is transferred on the interface in the same order as it was read from the media.

3.5 Skew

3.5.1 Cylinder to Cylinder Skew

Cylinder skew is the sum of the sectors required for physically moving the heads (csms), which is a function of the formatted block length and recording density (notch #), and reassign allowance sectors (ras = 3) used to maintain optimum performance over the normal life of the drive.

Note: The values in the Mode Page 3 'Cylinder Skew Factor' are notch specific non-synchronized spindle mode values. The value for notch 1 is returned when the Active Notch is set to 0.

						Notch #

User bytes / logical	1	2	3	4	5		6	7	8	9	10
block

256	42	42	42	40	38		36	36	36	36	32

512	28	28	27	26	25		24	24	23	22	21

520	26	26	26	26	24		24	23	22	22	21

522	26	26	26	25	24		24	23	22	22	20

524	26	26	26	25	24		24	23	22	22	20

528	26	26	26	25	24		24	23	22	22	20

600	24	24	24	23	22		22	21	20	20	20

688	22	22	22	21	20		20	20	20	18	18

744	21	21	21	20	20		20	18	18	17	17

Note: Contact an IBM Customer Representative for values at other formatted block lengths.

Table 8. Optimal Cylinder Skew for several block lengths

In order to increase the likelihood that equivalent LBA's on two or more devices are located at the same relative physical position when the devices are used in a synchronized spindle mode, cylinder skew is calcu- lated differently. The cylinder skew calculations do not take into account known defective sites. T o prohibit revolutions from being missed on cylinder crossings by drives formatted while in a synchronized spindle mode, an extra allowance for 6 defects is added that is not added when optimally formatted in a non- synchronized mode.

3.5.2 Track to Track Skew

Note: The values in the SCSI Mode Page 3 'Track Skew Factor' are notch specific values. The value for notch 1 is returned when the Active Notch is set to 0.

Page 46 of 87

I B M Corporation

Source filename=PERFORM

Image 46

Contents Form Factor Disk Drive Version BM Corporation Preface Source filename=STSSHEXT When Reliability Operating LimitsContaminants Acoustic Levels Source filename=STSSHEXT Interface Controller Features FeaturesGeneral Features DescriptionReliability Features ModelsSpecifications GeneralUser bytes/logical block ub/lba User bytes/sector ub/sctSectors/logical block sct/lba Sectors/track sct/trkCapacity Equations For Each NotchFor Entire Drive Input Voltage + 5 Volts Supply Power Requirements by Model1 C1x Models + 1 2 Volts SupplyExample 3. Power Calculation Power Calculation ExamplesExample 1. Calculate the mean 12 volt average current Things to check when measuring 12 V supply current Example 4. Calculate the 12 volt peak currentVolt current during read/write operations C1x Models Typical 12 volt current C1x Models Typical 12 volt spin-up current C1x Models 2 C2x Models Power Calculation Examples Example 4. Calculate the 12 volt peak current Volt current during read/write operations C2x Models Typical 12 volt current C2x Models Typical 12 volt spin-up current C2x Models 3 C4x Models Power Calculation Examples Example 4. Calculate the 12 volt peak current Volt current during read/write operations C4x Models Typical 12 volt current C4x Models Typical 12 volt spin-up current C4x Models CxB Models Power supply methods4.2 DC/DC Converter Grounding Requirements of the Disk Enclosure Hot plug/unplug supportM Corporation Bring-up Sequence and Stop Times Event Nominal MaximumBring-up Sequence Times and Stop Time for C2x Models Source filename=PERFORM Workload Definition PerformanceEnvironment Definition # of segments Ub/lba +Random Command Execution TimeSequential Basic Component DescriptionsData Transfer to/from Disk Comments Data Transfer to/from SSA LinkApproximating Performance for Different Environments Theoretical Data Sector Transfer RateWhen Adaptive Caching is Enabled When Read Caching is EnabledWhen Write Caching is Enabled When Read-ahead is EnabledReordered Commands When No Seek is RequiredFor Queued Commands Back-To-Back CommandsCylinder to Cylinder Skew SkewTrack to Track Skew Idle Time Functions Predictive Failure Analysis Servo Run Out MeasurementsServo Bias Measurements Channel CalibrationSave Logs and Pointers Command Timeout LimitsDisk Sweep M Corporation Small Form Factor Models CxC Weight and DimensionsMechanical ClearancesDimensions are in millimeters Location of Side Mounting Holes of C4C Models Source filename=MECHANIC Unitized Connector Locations Source filename=MECHANIC Carrier Models CxB Dimensions CxB Models M Corporation Handle Docking and Ejection System Auto-docking Assembly Side Rails Side Rail Positioning Electrical Connector and Indicator Locations E D Locations front view CxB Models M CorporationSSA Unitized Connector Electrical InterfaceCarrier Connector PinRow Option Pins and Indicators SSA Link Electrical CharacteristicsSSA Link Cable Write Protect Option Port Pin Device Activity Pin/Indicator Option Port PinDevice Fault Pin/Indicator Option Port Pin Ground long Option Port Pin12 12V Charge and 5V Charge Power Port pin 1 Front Jumper ConnectorEarly Power Off Warning or Power Fail Power Port Pin Programmable pin 1 Option Port PinSpindle Synchronization Over Sync Hard-wire M Corporation Source filename=RELIABLE Power On Hours Examples Error DetectionSeek Error Rate ReliabilityMaximum on/off cycles Power on/off cyclesUseful Life Product LifeSpql Shipped product quality level Install Defect FreeMean Time Between Failure *MTBF Sample Failure Rate ProjectionsInstall Defect Free percentage Percent Periodic MaintenanceConnector Insertion Cycles ESD ProtectionTemperature Measurement Points Operating LimitsMaximum Reliability P F E TTemperature Measurement Points for all Models bottom view Vibration and ShockOutput Vibration Limits Drive Mounting GuidelinesOperating Vibration Nonoperating Vibration V4SOperating Shock ContaminantsNonoperating Shock Upper Limit Sound Power Requirements Bels for C4x Models Acoustic LevelsSource filename=STANDARD Standards SafetyElectromagnetic Compatibility EMC M Corporation Bibliography Serial Storage Architecture S S a P H Transport