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Synonymharddiskgenerallyreferstocomputerharddisk

Technicalparameters

1,capacity

Asthedatastorageofcomputersystem,capacityisthemostimportantofharddiskParameters.

Thecapacityoftheharddiskisinmegabytes(MB)orgigabytes(GB),1GB=1024MB,1TB=1024GB.However,theharddiskmanufacturerusuallytakes1G=1000MBinthenominalharddiskcapacity,sothecapacityweseeintheBIOSorwhenformattingtheharddiskwillbesmallerthanthemanufacturer’snominalvalue.

Thecapacityindexoftheharddiskalsoincludesthesingle-diskcapacityoftheharddisk.Theso-calledsinglediskcapacityreferstothecapacityofasinglediskofaharddisk.Thelargerthesinglediskcapacity,thelowertheunitcostandtheshortertheaverageaccesstime.Forusers,thecapacityoftheharddiskislikethememory.Inadditiontosimpleroperations,theWindowsoperatingsystemhasalsobroughtaboutanincreaseinfilesizeandnumber.Someapplicationswilleatuphundredsofmegabytesofharddiskspaceatanytime,andthereisagrowingtrend..Therefore,itiswisetoadvanceappropriatelywhenbuyingharddrives.Inthefirsttwoyears,mainstreamharddriveswere320Gand500G,andlarge-capacityharddrivesabove750Ghavealsobeguntospread.In2007,large-capacityharddrivesof1TBbegantoappear.

2,Rotationspeed

RotationlSpeed​​(RotationlSpeed​​orSpindlespeed)istherotationspeedofthemotorspindleintheharddisk,thatis,theharddiskplatterinoneminuteThemaximumnumberofrevolutionsthatcanbecompletedwithin.Thespeedofrotationisoneoftheimportantparametersindicatingthegradeoftheharddisk.Itisoneofthekeyfactorsthatdeterminetheinternaltransmissionrateoftheharddisk,anditdirectlyaffectsthespeedoftheharddisktoalargeextent.Thefastertherotationspeedoftheharddisk,thefastertheharddiskcanfindfiles,andthetransmissionspeedoftherelativeharddiskwillbeimproved.Theharddiskspeedisexpressedinrevolutionsperminute,andtheunitisexpressedasRPM.RPMistheabbreviationofRevolutionsPerminute,whichisrevolutionsperminute.ThelargertheRPMvalue,thefastertheinternaltransferrate,theshortertheaccesstime,andthebettertheoverallperformanceoftheharddrive.

Thespindlemotoroftheharddiskdrivestheplatterstorotateatahighspeed,generatingbuoyancytomaketheheadfloatabovetheplatters.Tobringthesectorofdatatobeaccessedbelowthehead,thefasterthespeed,theshorterthewaitingtime.Therefore,therotationalspeedlargelydeterminesthereadspeedoftheharddisk.

Thespeedofordinaryharddisksforhomeuseisgenerally5400rpmand7200rpm.High-speedharddisksarethefirstchoicefordesktopusers;fornotebookusers,theyaremainly4200rpmand5400rpm,althoughsomecompanieshavealreadyreleased7200rpm.However,itisstillrelativelyrareinthemarket;serverusershavethehighestrequirementsforharddiskperformance.TheSCSIharddisksusedinserversbasicallyuse10000rpm,even15000rpm,andtheirperformanceismuchhigherthanthatofhouseholdproducts.Ahigherspeedcanshortentheaverageseektimeandactualreadandwritetimeoftheharddisk,butwiththecontinuousincreaseoftheharddiskspeed,italsobringsnegativeeffectssuchastemperaturerise,motorspindlewear,andworkingnoise.Thespeedofnotebookharddisksislowerthanthatofdesktopharddisks,whichisaffectedtoacertainextentbythisfactor.Theinternalspaceofthenotebookissmall,andthesizeofthenotebookharddisk(2.5inches)isalsodesignedtobesmallerthanthatofthedesktopharddisk(3.5inches).Thetemperaturerisecausedbytheincreaseinspeedputshigherrequirementsontheheatdissipationperformanceofthenotebookitself;thenoisebecomeslarger,Andmusttakenecessarynoisereductionmeasures,thesehaveputforwardmorerequirementsonthenotebookharddiskmanufacturingtechnology.Atthesametime,theincreaseinspeed,whiletheothersremainunchanged,meansthatthepowerconsumptionofthemotorwillincrease,themoreelectricityisconsumedperunittime,andtheworkingtimeofthebatteryisshortened,sothattheportabilityofthenotebookwillbeaffected.Therefore,notebookharddrivesgenerallyusearelativelylow-speed4200rpmharddrive.

3.Accesstime

AverageAccessTime(AverageAccessTime)referstotheheadfromthestartingpositiontothetargettrackposition,andfromthetargettrackThetimerequiredtofindthedatasectortobereadandwritten.

Theaverageaccesstimereflectsthereadandwritespeedoftheharddisk,whichincludestheseektimeandwaitingtimeoftheharddisk,namely:averageaccesstime=averageseektime+averagewaitingtime.

Theaverageseektimeoftheharddisk(AverageSeekTime)referstothetimerequiredfortheheadoftheharddisktomovetothedesignatedtrackonthedisksurface.Thistimeisofcourseassmallaspossible.Theaverageseektimeofaharddiskisusuallybetween8msand12ms,whileaSCSIharddiskshouldbelessthanorequalto8ms.

Thewaitingtimeoftheharddisk,alsoknownasthelatency(Latency),referstothetimethattheheadisalreadyinthetracktobeaccessedandwaitingforthesectortobeaccessedtorotatebelowthehead.Theaveragewaitingtimeishalfofthetimerequiredforthedisctorotateoneround,andshouldgenerallybelessthan4ms.

4.Transferrate

DataTransferRateThedatatransferrateoftheharddiskreferstothespeedatwhichtheharddiskreadsandwritesdata,inmegawordsKnotspersecond(MB/s).Harddiskdatatransferrateincludesinternaldatatransferrateandexternaldatatransferrate.

InternalTransferRate,alsoknownasSustainedTransferRate,reflectstheperformanceoftheharddiskbufferwhenitisnotinuse.Theinternaltransferratemainlydependsontherotationspeedoftheharddisk.

ExternalTransferRateisalsocalledBurstDataTransferRateorinterfacetransferrate.ItisnominallythedatatransferbetweenthesystembusandtheharddiskbufferTheexternaldatatransferrateisrelatedtothetypeofharddiskinterfaceandthesizeoftheharddiskcache.

ThemaximumexternaltransferrateofFastATAinterfaceharddrivesis16.6MB/s,whileUltraATAinterfaceharddrivesreach33.3MB/s.

TheharddiskusingSATA(SerialATA)portisalsocalledserialharddisk,whichisthetrendofPCharddiskinthefuture.In2001,theSerialATACommittee,composedofIntel,APT,Dell,IBM,Seagate,andMaxtor,formallyestablishedtheSerialATA1.0specification.In2002,althoughserialATArelatedequipmenthasnotbeenofficiallylisted,theSerialATAcommitteehaspreemptivelyestablishedtheSerialATA2.0specification.SerialATAadoptsserialconnectionmode.SerialATAbususesembeddedclocksignalandhasstrongererrorcorrectioncapability.Comparedwiththepast,itsbiggestdifferenceisthatitcanchecktransmissioninstructions(notjustdata).Errorsarefoundtobeautomaticallycorrected,whichgreatlyimprovesthereliabilityofdatatransmission.Theserialinterfacealsohastheadvantagesofsimplestructureandsupportforhotswapping.

5.Cache

Cachememoryisamemorychipontheharddiskcontrollerwithextremelyfastaccessspeed.ItisaharddiskBufferbetweeninternalstorageandexternalinterface.Sincetheinternaldatatransferspeedoftheharddiskisdifferentfromthetransferspeedoftheexternalinterface,thecacheactsasabufferamongthem.Thesizeandspeedofthecacheareimportantfactorsdirectlyrelatedtothetransmissionspeedoftheharddisk,whichcangreatlyimprovetheoverallperformanceoftheharddisk.Whentheharddiskaccessesfragmenteddata,itneedstoconstantlyexchangedatabetweentheharddiskandthememory.Withalargecache,thosefragmenteddatacanbetemporarilystoredinthecache,reducingtheloadontheexternalsystemandincreasingthedatatransmissionspeed

Classification

1.Memorycommunication

Therearetwotypes:XTtype(ieDMAmode)andATtype(ieinterruptdrivemode)kind.

2.Magneticheaddrive

Therearetwotypes:steppermotordriveandvoicecoilmotordrive.

Thestructureofthesteppingmotordrivemechanismiscompactandthecontrolissimple,buttheentiredrivingpositioningsystemisopen-loopcontrol,andthesteppingmotorisdrivenbypulsesignals,sothepositioningaccuracyisrelativelylowandtheaccesstimeislonger;

Thevoicecoilmotorisalinearmotor,whichcandirectlydrivetheheadforlinearmotion.Theentirepotatodynamicpositioningsystemisaclosed-loopadjustmentautomaticcontrolsystemwithspeedandpositionfeedback,withfastdrivingspeedandhighpositioningaccuracy.Advanceddiskdrivesgenerallyusevoicecoilmotordriveandservodiskpositioning.

Thediscdiameterandcapacityare5.25inches,3.5inches,2.5inches,1.8inchesand1.3inches,andthesmallestisthesizeofafingernail.

Fromtheappearancesize,therearethreetypes:full-height,half-heightandthin.

Structure

Theharddiskisoneofthemostimportantmemoryinacomputer.Mostofthesoftwareneededforthecomputertofunctionproperlyisstoredontheharddrive.Becausethestoragecapacityofharddiskislarge,itisdifferentfrommemoryandopticaldisk.Harddisksarestoragedevicesbasedonhardrotatingdisksusedoncomputers.Itstoresandretrievesdigitaldataonaflatmagneticsurface.

Magnetichead

Themagneticheadisthemostexpensivecomponentintheharddisk,anditisalsothemostimportantandcriticalpartoftheharddisktechnology.Thetraditionalmagneticheadisanelectromagneticinductionmagneticheadthatcombinesreadingandwriting.However,harddiskreadingandwritingaretwocompletelydifferentoperations.Forthisreason,thistwo-in-onemagneticheadmustbedesignedwithbothreadingandwriting.Thesetwocharacteristicsresultinthelimitationofharddiskdesign.MRmagneticheads(Magnetoresistiveheads),thatis,magnetoresistivemagneticheads,useaseparateheadstructure:writeheadsstillusetraditionalmagneticinductionheads(MRheadscannotperformwriteoperations),andreadheadsusenewMRheads.Theso-calledinductivewritingandmagnetoresistivereading.Inthisway,duringthedesign,thedifferentcharacteristicsofthetwocanbeoptimizedseparatelytoobtainthebestread/writeperformance.Inaddition,theMRheadsensesthesignalamplitudethroughchangesinresistanceratherthanchangesincurrent,soitisverysensitivetosignalchanges,andtheaccuracyofreadingdataisalsoimprovedaccordingly.Andsincetheamplitudeofthereadsignalhasnothingtodowiththetrackwidth,thetrackcanbemadeverynarrow,therebyincreasingthediscdensityto200MB/inch2,whilethetraditionalmagneticheadcanonlyreach20MB/inch2,whichisalsoanMRheadThemainreasonforbeingwidelyused.MRheadshavebeenwidelyused,andGMRheads(GiantMagnetoresistiveheads)madeofmaterialswithamulti-layerstructureandbettermagnetoresistiveeffecthavegraduallybecomepopular.

Track

Whenthediskisspinning,iftheheadisheldinoneposition,eachheadwilldrawacirculartrackonthesurfaceofthedisk.Thesecirculartracksarecalledtracks.Thesetracksareinvisibletothenakedeyeatall,becausetheyareonlysomemagnetizedareasonthedisksurfacethataremagnetizedinaspecialway,andtheinformationonthediskisstoredalongsuchtracks.Adjacenttracksarenotclosetoeachother.Thisisbecausewhenthemagnetizationunitsaretooclose,themagnetismwillaffecteachother,andatthesametimeitwillalsocausedifficultiesforthemagneticheadtoreadandwrite.A1.44MB3.5-inchfloppydiskhas80tracksononeside,andthetrackdensityontheharddiskismuchgreaterthanthisvalue,usuallytherearethousandsoftracksononeside.

Thesurfaceofthediskiscoatedwithamagneticmediumforrecording,andwhatappearsunderthemicroscopeisamagneticparticle.Thepolarityoftinymagneticparticlescanbequicklychangedbythemagnetichead,andcanbemaintainedstablyafterthechange.Thesystemdistinguishes0or1inthebinarysystemthroughchangesinmagneticfluxandmagnetoresistance.Itispreciselybecausealloperationsareperformedundermicroscopicconditions,soiftheharddiskissubjectedtoexternalforceshockswhilerunningathighspeed,itmaycauseirreversibledatalossduetotheheadslapsonthesurfaceofthedisk.Inaddition,theuniaxialanisotropyandvolumeofthemagneticparticleswillobviouslyaffectthethermalstabilityofthemagneticparticles,andthelevelofthermalstabilitydeterminesthestabilityofthemagneticparticlestate,thatis,thecorrectnessofthestoreddata.Sexandstability.However,theuniaxialanisotropyandvolumeofmagneticparticlescannotbeincreasedblindly.Theyarelimitedbythewritefieldthatthemagneticheadcanprovideandthesignal-to-noiseratioofthemedium.

Sectors

Eachtrackonthediskisequallydividedintoanumberofarcs.Thesearcsarethesectorsofthedisk.Asectorcanstore512bytesofinformation.Whenthediskdrivereadsandwritesdatatothedisk,itmusttakethesectorastheunit.1.44MB3.5-inchfloppydisk,eachtrackisdividedinto18sectors.

Cylinder

Aharddiskisusuallycomposedofasetofoverlappingdisks,eachdisksurfaceisdividedintoanequalnumberoftracks,andfromtheouteredge"0"startswiththenumber,andthetrackswiththesamenumberformacylinder,whichiscalledthecylinderofthedisk.Thenumberofcylindersonadiskisequaltothenumberoftracksonadisk.Sinceeachdisksurfacehasitsownhead,thenumberofdisksurfacesisequaltothetotalnumberofheads.Theso-calledCHSoftheharddisk,namelyCylinder(cylinder),Head(head),Sector(sector),aslongasthenumberofCHSoftheharddiskisknown,thecapacityoftheharddiskcanbedetermined,andthecapacityoftheharddisk=thenumberofcylindersandthenumberofsectors.Thenumberis512B.

Howtouse

Whentheharddiskisworking,neverforciblyturnoffthepower.Turningoffthepowerwhentheharddiskisworkingwillcausephysicaldamagetotheharddiskanddataloss.Inaddition,therearehigh-speedrunningpartsintheharddisk.Ifthehigh-speeddiskisshutdownforcibly,thehigh-speeddiskwillsuddenlystop,andifitisturnedonimmediatelyaftertheshutdown,itismorelikelytocausedamagetotheharddisk.Sodon'tturnonthecomputeragainimmediatelyaftershuttingdown.Turnitonagaininatleasthalfaminute.

Whentheharddiskisworking,trytoavoiditsshock,becausethedistancebetweenthemagneticheadandthemagneticdiskisveryclose.Ifitissubjectedtoseverevibration,themagneticheadwillhitthemagneticdisk,andthemagneticheadmayscratchthemagneticdisk.Chipsmayalsocausecompletedamagetothehead,makingtheentireharddriveunusable.

Intheprocessofusingtheharddisk,manyusersoftencompressinthe"diskspacemanagement".Usethisprogramtocompresstheharddisk.Thiswillcausethecompressedvolumefiletocontinuetogrow.Theteamalsosloweddown,andthenumberofreadsandwritesincreased,whichwouldaffecttheheatgenerationandstabilityoftheharddisk.Soitwillleadtoareductioninservicelife.So,iftheharddiskisenough,thereisnoneedtousethisprogram.

Correctmaintenance

Theharddiskisveryafraidofdust.Ifdustisattractedtothecircuitboard,itwillcausetheharddisktoworkunstableorcausedamagetointernalparts.Thefunctionalworkingstatusoftheharddiskhasagreatrelationshipwiththelifeandtemperature.Ifthetemperatureistoohighortoolow,theclockfrequencyofthecrystaloscillatorwillchange,whichwillcausethecircuitcomponentstomalfunction.Ifthetemperatureistoolow,itwillcausetheairThemoisturecondensesonthecomponent,causingashortcircuit.

Secondly,wewillorganizeyourharddriveregularly.Thiswillincreasethespeedofyourharddrive.Iftherearetoomanyjunkfilesontheharddisk,thespeedwillslowdownandthetracksmaybedamaged.However,donotcleanupintwodays,asthiswillalsoreducethelifeoftheharddrive.

Finally,itisanti-virus.Virusesarethebiggestthreattothefilesstoredontheharddrive.Therefore,wefoundthatthevirusshouldberemovedintimeandtrynottoformattheharddisk.

Theabovearesometipsforusingandmaintainingharddrives.Ifeveryonecandothis,yourharddriveswillbemoredurable.

Mattersneedingattention

1.Don’tshutdownsuddenlyduringwork

Whentheharddiskstartstowork,itusuallyspinsatahighspeed.Amongthem,ifwesuddenlyturnoffthepowerhalfway,itmaycauseviolentfrictionbetweentheheadandtheplattersanddamagetheharddisk.Therefore,wemustavoidasuddenshutdown.Whenshuttingdown,youmustpayattentiontowhethertheharddiskindicatoronthepanelisstillflashing.Onlyaftertheindicatorstopsflashingandtheharddiskreadandwriteends,youcanturnoffthecomputer'spowerswitch.

2.Preventdustfromentering

Dustcancausegreatdamagetotheharddisk.Thisisbecauseinadustyenvironment,theharddiskiseasytoattractThedustparticlesintheaircauseittoaccumulateontheinternalcircuitcomponentsoftheharddiskforalongtime,whichwillaffecttheheatdissipationoftheelectroniccomponents,causingthetemperatureofthecircuitcomponentstorise,causingleakageorburningofthecomponents.

Inaddition,dustmayalsoabsorbmoisture,corrodetheelectroniccircuitsinsidetheharddisk,andcausesomeinexplicableproblems.Therefore,althoughthevolumeofdustissmall,theharmtotheharddiskcannotbeunderestimated.Therefore,itisnecessarytomaintainenvironmentalsanitationandreducethehumidityanddustcontentintheair.Remember:generalcomputeruserscannotdisassembletheharddiskcoverbythemselves,otherwisethedustintheairwillentertheharddiskandscratchthediskorthemagneticheadwhenthemagneticheadreadsorwrites.

3.Topreventthetemperaturefrombeingtoohighortoolow

Temperaturealsoaffectsthelifeoftheharddisk.Acertainamountofheatisgeneratedwhentheharddiskisworking,andthereisaheatdissipationproblemduringuse.Thetemperatureshouldbe20~25℃,toohighortoolowwillcausetheclockfrequencyofthecrystaloscillatortochange.Temperaturecanalsocausefailureofharddiskcircuitcomponents,andmagneticmediacanalsocauserecordingerrorsduetothermalexpansion.Ifthetemperatureistoolow,themoistureintheairwillbecondensedontheintegratedcircuitcomponents,causingashortcircuit;whenthehumidityistoohigh,thesurfaceoftheelectroniccomponentsmayabsorbawaterfilm,oxidizeandcorrodetheelectroniccircuit,resultinginpoorcontactorevenshortcircuit,Itwillalsocausethemagneticforceofthemagneticmediumtochange,causingdatareadingandwritingerrors;toolowhumidity,itiseasytoaccumulatealargeamountofstaticchargegeneratedbytherotationofthemachine,whichwillburnouttheCMOScircuit,attractdustanddamagetheheadandscratchthedisk.piece.Inaddition,trynottoplacetheharddiskclosetostrongmagneticfields,suchasspeakers,speakers,motors,radios,mobilephones,etc.,soasnottodamagethedatarecordedbytheharddiskduetomagnetization.

Causeoffailure

1.Harddiskcoolingfan

Consideringtheheatdissipationeffect,manypeoplehaveinstalledtheharddiskfortheircomputerHarddiskcoolingfans,butsomelow-endfans,itsvibrationisquiteobvious,cantransmitthevibrationtotheharddisk,inthelongrun,itwilldefinitelyhaveanimpactonthelifeoftheharddisk.

Second,CD-ROMdrive

ThereadingspeedofmainstreamCD-ROMdriveshasreachedmorethan50timesspeed.Vibrationwilldrivetheresonanceofthechassis,therebyaffectingtheworkoftheharddisk.Andthiskindofhigh-speedrotationgeneratesalotofheat,andtheopticaldriveissoclosetotheharddrive,theheatreleasedfromtheopticaldrivewillsurelyincreasethetemperatureoftheharddrive.

3.Dust

Dustdamagestheharddisk.Thedustdepositedontheharddiskcircuitboardwillseriouslyaffectthechiponthecircuitboard.Theheatdissipationcausesthetemperatureofthecomponentsonthecircuitboardtorise,whichinturncausesthechiptooverheatandburn.Inaddition,ifdustabsorbsmoisture,itiseasytocauseashortcircuit.

Four.Staticelectricity

Intheprocessofrepairingthecomputer,manypeopleholdtheharddiskwiththeirhands,butindryweather,people’sTensofthousandsofvoltsofstaticelectricitymayaccumulateonyourhands,andthestaticelectricityonyourhandsmaybreakdownthechipsonthecircuitboardandcausetheharddisktomalfunction.

V.Low-levelformatting

Ifthecomputerharddiskhasbadsectors,manynetizenshaveadoptedlow-levelformattingmeasures.Infact,low-levelformattingaffectstheharddisk.Thedamageislarge,itmaycausethespreadofbadsectorsonthedisk,andevencausethelossofharddiskparameters,makingtheharddiskunusable.

Six.Powersupply

Alow-qualitycomputerwillcausetheharddisktobedisturbedbyvoltagefluctuations,especiallywhentheharddiskisreadingandwritingoperations,ifThereisaproblemwiththepowersupply,andaharddiskcanbescrappedinaninstant.

Seven,magneticfield

Becausetheharddiskisadevicethatreliesonmagneticmediatorecorddata,ifitisinterferedbythemagneticfieldoftheexternalenvironment,itmaycausethediskDataislost,soitshouldbeasfarawayfromthemagneticenvironmentaspossible.

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