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R.Fontana,G.Decad,R.Biskeborn- IBMSystemsSeptember18,2017
Moore’sLawScalingRealitiesforStorageComponents:LTOTAPE,HDDandNAND
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 1
TOPICS
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 2
• Moore’slawforintegratedcircuits
• Moore’slawscalingappliedtostorage: bitarealdensityandcostperbit
• Bitarealdensityand$/gigabitstrendsforTAPE,HDD,andNAND(3and8yr periods)
• Costscalingdeviationsandotherproblems
• Summary
WhatisMoore’slaw?
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 3
• 1965:GordonMooreobservedthatthenumberoftransistors,resistorsandcapacitorsinanintegratedcircuit(IC)hadbeenincreasingexponentially(2xperyear); thisimpliedthattheunitcostofthetransistors,etc.,thatcouldbecrammedintoanICwasdecreasingexponentially
• 1975:MoorerefinedhisobservationandmadeprojectionthatICcomplexitywoulddoubleevery2years (withICcostremainingstatic)- thisbecameknownas‘Moore’sLaw’
• Theimplicationofthisistheunitcostofthetransistors,etc.,willdecrease2xevery2years
• Thereisacloseparalleltothisfordigitaldatastorage
Bits,arealdensityandscaling
Moore'sLawScalingRealitiesforStorageComponents 4
• Instoragearchitectures,dimensionsofthebits(the1’sand0’s)determinebitarealdensity
• Thus,bitsareanalogoustotransistors,resistors,etc.,andtheaggregateareaoftheallthebits,toanIC
• ForNAND,bitdimensionsarephotolithographicallydefined(moreakintotheparadigmbehindMoore’slaw)• Scalingmeansimprovementsinphotolithography(XandY)andotherICprocesses(X,YandZ)
• Formagneticstorage,thebitdimensionsareestablishedduringwritingthebits ontothemagneticmedium• Bitwidth(X)issetbythewidthofthewritehead(HDD)orshinglingpitch(TAPE,someHDD)• Bitlength(Y)issetbythewritingfrequencyandspeedofthemagneticmediumunderthehead• Scalingmeansnarrowerwrittentracksandshorterbitlength
Fontana,Decad,Biskeborn- IBMSystems
• Instoragetechnology,bitarealdensity(D) ideallyincreasesexponentiallywithanannualgrowthfactorof(1+α)• Year0: D=D0
• YearN: DN =D0 x(1+α)N
• Ifthecost/unitareaofstorageisconstant,thenthecostperbit(C) decreasesexponentiallywithanannualdecreasefactorof(1- β)• Year0: C=C0• YearN: CN =C0 x(1- β)N
• Andtherelationshipbetweenthe2factorsis:• β =α /(1+α)
• Thus,an‘ideal’Moore’slawICscalingequivalentforstoragecomponentswouldgive:• Bitarealdensitydoublingevery2years,i.e α =0.41(41%annualincrease)• Cost/unitofmediaarearemainingconstantè cost/bithalvesevery2years,i.e β =0.29(29%annualdecrease)
Moore’sexponentiallawforstorage:bitarealdensity,costperbit
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 5
• NANDincreasesareclosertoMoore’sat33%andshownodecreaseinthisrate
• LTOTAPEMEDIAdoubleson~3yearcycle,or25%annually,andshowsnoslowinginthisrate
• HDDincreasesare<<Moore’sscaling;8yearincreasesreducedto14%andshowsignificantslowinginrecenttimeframes
• Blu-rayADisstable,atmostincreasingslowly
0.1
1
10
100
1000
10000
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
AREA
LDEN
SITY(G
b/in
2 )
YEAR
HDD NAND LTOTAPEMEDIA
BD-RE
AREALDENSITY(Gbit/in2) 2008 2015 2016
8YEARANNUAL
%Δ
3YEARANNUAL
%Δ
1YEARANNUAL
%Δ
LTOTAPEMEDIA1 0.9 4.1 4.1 21% 25% 0%
HDD 380 1000 1100 14% 7% 10%
NAND 200 1500 2000 33% 33% 33%1.LTOproductson2yearproductcycle,2017LTO8productwillincrease1yearand8yearaverages
But…currentstoragearealdensitygainsarelessthanMoore’s41%*
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 6
*Intheperiod2003- 2011,HHDdensitydid growat39%/year
• 29%decreasesincostperbitarenotbeingachieved
• NAND$/GBshowsa3yearaveragedropof20%
• HDD$/GBshowsa3yearaveragedropof18%
• LTOTAPEMEDIA$/GB(distortedbyachangeinLTOdatasources)showsa10%drop
• Blu-raycostperbitisstable,nodrop
0.01
0.1
1
10
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
$/GB
YEAR
HDD NAND LTOTAPEMEDIA
100GBBD
50GBBD
25GBBD
BD-RE
$/GB 2008 2015 20168YEARANNUAL
%Δ
3YEARANNUAL
%Δ
1YEARANNUAL
%Δ
LTOTAPEMEDIA1 0.091 0.018 0.016 -19% -10% -10%
HDD 0.272 0.051 0.039 -21% -18% -23%
NAND 3.330 0.401 0.320 -25% -20% -20%1.Datasourcechangefrom2014to2015distortsLTOaverages
And…currently,reductionsincostperbitarelessthanMoore’s29%
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 7
• DiskcostisunitcostoftheHDDbrick,whichincludesplatters,heads,electronics,etc.
• Tapecostisforthemediacartridgeonly;drivecostistypicallyincludedinautomationandissignificantlylessthanthecostofthemedia
AnimportantdistinctionbetweenHDDandTAPE
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 8
0
5
10
15
20
25
30
35
40
0 5 10 15 20 25 30 35 40 45
AnnaulCost/BitDecrease-%
(βx10
0)
AnnualArealDensityIncrease- %(α x100)
IdealMoore’sLaw
%Arealdensityincrease/year(α)
%Costp
erbitde
crease/year(β)
Cost/BitReduction<Moore’sLawMetric(DevelopmentCost,MarketForces)
Cost/BitReduction>Moore’sLawMetric(SimpleScaling,MarketSharePressure)
$/GBandarealdensity‘dynamics’
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 9
cost/unitareaofstoragemediaisconstant
ThisplotisageneralizationofMoore’s-likeexponentialscalingforstorage.RecallthatGordonMoore’spredictionforIC’swasadoublingevery2years(the‘dot’)atconstantICcost
• LTOTAPE,NAND:8yrdatafollowaMoore’slawtrend,while3yrdatafallbelowit,implying(1)marketforcesand/or(2)greaterinvestmentwasneededforthegainindensity
• HDD:8yrand3yrdataareabovetheMoore’slawtrend,implying(1)marketforcecompetitionand/or(2)themodestarealdensitygainsdidnotdriveupcost
• Observation1: Historical8yrdatashows$/bitforalltechnologiesfellbetween20%to25%annually
• Observation2:Historical3yrdatashowslower$/bitreductionsforalltechnologiesrelativeto8yrdata
0
5
10
15
20
25
30
35
40
0 5 10 15 20 25 30 35 40 45
AnnaulCost/BitDecrease-%
(βx10
0)
AnnualArealDensityIncrease- %(α x100)
IdealMoore’sLaw
NAND
%Arealdensityincrease/year(α)
%Costp
erbitde
crease/year(β)
Cost/BitReduction>Moore’sLawMetric(SimpleScaling,MarketSharePressure)
(8yr)
(3yr)
LTOTAPE
(8yr)
(3yr)
HDD
Cost/BitReduction<Moore’sLawMetric(DevelopmentCost,MarketForces)
(8yr)
(3yr)
$/GBandarealdensity‘dynamics’
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 10
• Presentday storagecomponenttrendsarenotmeetingMoore’slawforICs• Annualdensityincreaseisnot41%,butrangesfrom10%to30% (dependingontechnology)• Costperbitdecreaseisnot29%,butcloserto10%to20%, (dependingontechnology)
• Critically,thecosttoproduceaunitareaofstorage isNOTremainingconstant,butratherisincreasing• Physicsandtherequiredlinewidthsassociatedwithscalingbitcellsareraisingdevelopmentcosts• Marketingforces
• Further,thelandscapeofstoragecomponentmanufacturersischanging• Fewercompetitors(bothHDDandTAPE)• Manufacturingcapacityconstraints(NAND)• Limitedmarket(Optical)
WhatarethescalingREALITIES
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 11
• Feynmanfamouslystatedin1959(theyearthefirstintegratedcircuitswerebuilt),‘thereisplentyofroomatthebottom,’i.e.youcanalwaysmakethingssmaller• 1959minimumfeatures~1500um• 2017minimumfeatures~0.015um• In60yearslinewidthsfellby~105 andcellareasfellby~1010
• 2017NANDchips(12mmx12mm)contain256x109 bits,whilechipsin1960contained1to5bits[1]
• Thus,for~50years,theMoore’slaw‘contract’hadbeen:reducecomponentcostperbitbyfinding‘roomatthebottom’withsmallerbitcelldevicesatthesamecostperunittotalstoragearea
• Inthelast5years,the‘art’ofmakingbitcellssmaller,though,hasincreasedthecostofaunitareaofstorage
[1]JackS.Kilby,MiniaturizedElectronicCircuits,UnitedStatesPatentOffice,USPatent3,138,743,filed6February1959, issued23June1964
And…costeffectivebit-scalingisbecomingmoredifficult
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 12
• TAPE:roomatthebottom,socontinuescaling(Moore’slaw)
• HDD:noroomatthebottom,soaddmoreplatters(notMoore’slaw)
• OPTICAL:someroomatthebottom,limitedbyλ,soaddmorelayers(notMoore’slaw)
• NAND:noroomatthebottom,soaddmorelayersatthemedialevel,butprocesslayerssimultaneously(closetoMoore’slaw)
40layers,ormoreNAND3DTLC40layers3bit/cell84nmx84nm3000Gbit/in2
HDD58nmx11nm1000Gbit/in2
ENTERPRISETAPE1350nmx47nm9Gbit/in2
LTOTAPE~3200nmx47nm4Gbit/in2
OPTICALBD-XL3layerlandrecording180nmdiameter75Gbit/in2
10TB3.5”drive7-8platters/~1.4TB/platter
1.2TBcartridge12platters/~0.1TB/platter
6TBCartridge,1000mtapelength
15TBcartridge,1100mtapelength
7TB12”wafer44012mmx12mmdies/~256Gb/die
Bitcelldimensions
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 13
• ArealDensityStrategy isaddingmorelayers
• Cost/bitreductionsaremaintainedprovidedalllayersareprocessedinasinglesteptoformindividualstackedbitcells
• ContinuedscalingandMoore’slawarelimitedbyabilitytocontinuallydoublenumberoflayers
• Densityincreaseof4Xto~128layersand4bitspercellareintheoffing
• Costperbitdecreaseof4Xlesslikelysince‘tiered’processingoflayersisrequired,i.e.processthefirst64layersandthenthesecond64layers,etc.
40layersNAND3DTLC40layers3bit/cell84nmx84nm3000Gbit/in2
7TB12”wafer44012mmx12mmdies~256Gb/die
NAND
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 14
• Volumetricstrategy isaddingmorediskplatters,withminimalincreaseinaerialdensity
• Cost/ bitintransitioningfrom4TBto10TBcapacitywasmanagedbymovingfrom4to7or8platters,butthismeantincreasingthemanufacturingareaforcomponents(headsanddisksurfaces)
• ScalingandhenceMoore’slawgainsarelimitedbyabilitytocontinuallydoublenumberofplatters
• Densityincreaseof2Xpossiblebutadditionofmoreplatterswillbedifficult
• Cost/ bitreductionshavelimitedscalingpotentialduetodifficultyofincreasingarealdensity,e.g.HAMR
HDD58nmx11nm1000Gbit/in2
10TB3.5”Drive7-8platters/~1.4TB/platter
HDD
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 15
source:idema.org
HAMRisneededtoenablesignificantHDDbitlengthscaling
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 16
shrinkingHDDbitdimensionsfaceschallengesinbothdirections:
X(SMR)andY(KBPI)
• ArealDensityStrategy isclassicalplanarscaling,i.e.makingthebitcellsmaller
• Costlikelyislikelytobemanagedsince(1)classicalscalingisused,(2)TAPEusesHDDexistingtechnology(‘nonewphysics’),and(3)lengthscalesandmediaparticlesizeswillscaleforthefuture
• Costdynamicsmaybeinfluencedbymarketsources
• 4Xdensityincreasesproviding>40TBcartridgecapacitiesareonly4yearsonthehorizon
• TheFuture
EnterpriseTAPE1350nmx47nm9Gbit/in2
LTOTAPE3200nmx47nm4Gbit/in2
6TBcartridge,1000mtapelength
15TBcartridge,1100mtapelength
TAPEDemonstration(2017)103nmx31nm207Gbit/in2
TAPE
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 17
TapehasroomtocontinuebitscalinginbothXandYdirections
TAPEscalingrequires‘nonewphysics’
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 18
• Moore’slawforICs(doublingdensityevery2years,andcost/bithalvingeverytwoyears)isnotbeingachievedbyLTOTAPE,HDD,NAND (NANDbeingtheclosest)
• Bitcellscalingisloosingcostefficiency• Physics,e.g.HAMR• Processingsmallerfeatures- nano technologylimits(HDD,NAND)• Cost-per-bitreductionsaretrendingtolessthan20%/year
• Marketforcesarenowimpacting$/GBreductions• 3yearand8yeartrendsshowdecreasein$/GBreductionsforalltechnologies• Thereisanunder-capacityinNAND(notenoughfactoriestomeetHDDdemandinforeseeablefuture)• HDDmarkethasshiftedfrompersonaldevicestodatacenterapplications• Thereistapeconsolidation(1drivemanufacturer,2mediasuppliers)
SUMMARY
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 19
APPENDIX
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 20
2008 2009 2010 2011 2012 2013 2014 2015 2016
HDD
Units(HDDmillions) 540 557 652 620 577 551 564 470 425
PBShipped(PB) 125000 200000 330000 335000 380000 470000 549000 565000 693000
ArealDensity(Gb/in2) 380 530 635 750 750 900 900 1000 1100
Revenue($billions) 34.0 34.0 33.0 33.5 37.5 33.4 33.4 28.3 26.8
$/GBShipped 0.272 0.170 0.100 0.100 0.100 0.071 0.061 0.051 0.039
NAND
Wafers(12“-millions) 7.3 8.3 9.7 11.3 12.1 13.7 14.8 15.9 17.0
PBShipped(PB) 3000 5430 10464 18600 28000 39000 62500 83000 120000
ArealDensity(Gb/in2) 200 280 330 550 550 850 1200 1500 2000
Revenue($billions) 10.1 12.1 18.5 21.5 22.0 24.0 32.2 33.2 38.7
$/GBShipped 3.33 2.23 1.77 1.16 0.78 0.615 0.515 0.401 0.320
LTOTAPEMEDIA
Units(Cartmillions) 27.1 24.3 25.0 24.3 23.4 21.6 22.2 19.4 19.4
PBShipped(PB) 11050 11960 15340 18420 20680 24270 30100 33020 40320
ArealDensity(Gb/in2) 0.9 0.9 1.2 1.2 2.1 2.1 2.1 4.1 4.11
Revenue<SCCG.com>($billions)2 1.0 0.7 0.7 0.7 0.62 0.54 0.50
Revenue<LTO.org>($billions)2 0.59 0.65
$/GBShipped 0.0905 0.0585 0.0456 0.0380 0.0300 0.0222 0.0166 0.0177 0.0162
1.LTOon2yearproductcycleforarealdensity2.LTOdatasourceshiftsfromSCCGtoLTOConsortiumin2015.Datadiscontinuityforrevenueand$/GBin2014-2015transition
StorageLandscape- 9YearHistory
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 21
• ArealDensityStrategy isaddingmorestoragelayersontheplasticdisksubstrate
• Costperbitlikelynotwellmanaged,sincethepatterningorprocessingofeachstoragelayerisdoneindividually
• A2-sided3+3layerdiskmayhave2Xthecapacityofthesinglesided3layerdiskbutatcloseto2xthecostofthesinglesided3layerdisk.
• Scaling,andhenceMoore’slawgeometricfigureofmeritgains,arelimitedbyabilitytosimultaneouslyprocessindividuallayers
• Landandgrooverecordingwilllikelyincreasedensityby1.5Xattheexpenseoferrorrate
• Costperbitreductionshavelimitedpotentialwithlandandgrooverecording,providingthepotentialforonlyaonetime30%reductionincostperbit
OpticalBD-XL3layerlandrecording180nmdiameter75Gbit/in2
1.2TBCartridge12disks~0.1TB/platter
OpticalBD-XL
Fontana,Decad,Biskeborn- IBMSystems Moore'sLawScalingRealitiesforStorageComponents 22