NCR RealPOS 40 - Chapter 6: Solid State Drive Optimization; Introduction

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Chapter 6: Solid State Drive Optimization
Introduction
WhenyoudeleteafilefromyoursystemthehostonlydeletesapointerintheOSfile
system,butdoesnotphysicallyerasethedatafromthedrive.Whilethedeleteddata
nolongerappearsvalidtotheOS,itstillappearsvalidtothedrivefirmware.Sinceno
runtimeisspentbythedrivetophy
sicallyerasethetargeteddatathismakestheOS
operationfast.Intermsofperformancethismethodmaybeadvantageousfor
traditionalharddiskdrives;however,itprovidesanunnecessaryconstraintforsolid‐
statedrives(SSDs)becausetheyofferhigherlevelsofperformancewhentheyhold
lessdata.
Toremovethisunwante
dconstraint,IntelprovidestheIntel®SSDOptimizerforits
34nmseriesofX25‐MandX18‐Msolid‐statedrives.Thisfeaturegivestheabilityto
retainoutofboxperformancelevelsoverthelifeofthedrive.
Unliketraditionalharddiskdrives,itisadvanta
geoustotellanSSDwhenyoudelete
files.Atsomepointevery4KBpagehasbeenwrittentoonce,andyouhavetostart
overwritingoldexistingdata.Unlikespinningmedia,Flashmediacannotsimply
overwriteexistingdataandmustfirstperforma512KBblockerase.Tooverwrite
existingdata,anSSDrequ
iresalongerread‐modify‐writeoperationwhichiswhy
writeperformanceisreducedasthedrivefills.