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Magnetic Tape: Technology
Dr. Richard H. Dee
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 2
Outline
› Mass Storage Technologies
› Density Trends for Tape (&Disk)
› Capacities/Data rates
› Terabytes on a tape
› Magnetic Recording
› The Media and Heads
› Summary
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 3
Mass Storage Technologies
› Magnetic Tape
› Optical Tape
› Magnetic Disk
› Optical Disk (DVD?)
› MEMS Probe
› 3D. Holographic, 2-electron…
› Other
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 4
Magnetic Disk› Technology leader (areal density)
› Aggressive storage density growth rate continues but more slowly–100+% CAGR to 60% or even less CAGR predicted–Still a “spoiler” for other storage technologies
› Continued areal density progress influenced by superparamagnetic effect–New approaches to media, heads required, applied, in development
• Research claims up to 50 Tb/in2 !?
› Consumer products effect development, market, cost e.g. “ATA-class disk”
› ATA-class (low-cost) disk can support commercial data processing environment–Utilized in StorageTek’s “BladeStore” disk subsystem with fiber channel rates
CAGR: Compound Annual Growth RateATA: Advanced Technology Attachment
M. Leonhardt 4-9-02
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 5
Magnetic Tape› Technology follower - areal density trend lags disk
–Increased defect tolerance–Uses higher media surface area to compete –Volumetric density the tape metric
› Continues to leverage magnetic disk technologies as appropriate
› Opportunity for more aggressive operating points
› Media improvements are key to advancement
› 1TB cartridge capacity product roadmaps target 2005-2007 –Multi-TB’s planned
› Holding on to cost advantage over other storage subsystems types -- low end under pressure from alternatives.
M. Leonhardt 4-9-02
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 6
Tape vs. Disk -- “Is tape dead?” -- NO!Reference: Information Storage Industry Consortium (INSIC) Tape Roadmap 2002
› 10 year outlook has tape maintaining its competitive position with disk (within a narrowed market)–Present capacity, data rate ratios can be maintained–Slow down in magnetic disk density advances factored in -- 60% CAGR–Continuing disk innovation assumed -- gets tougher 5-10 years out
M. Leonhardt 4-9-02
282828Data Rate Ratio (Disk/Tape)3.33.33.3Capacity Ratio (Tape/Disk)
TB30.30.03Disk Drive Single Platter CapacityTB1010.1Tape Cartridge Capacity
Unit201120062001Year
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 7
The ‘S’ Curve of Technology Progress
T. Schwarz, IEEE-NASA MSS Conference 2000
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 8
Areal Density Perspective
1990 1995 2000 2005 20100.1
1
10
100
1000
10000
Charap's Superparamagnetic Limit
||
⊥Perpendicular Recording 1 Tbit/in2
100 Gbit/in2
40-50 Tbit/in2 Single Particle Superparamagnetic Limit
LABORATORY DEMOS
Historical 60% CGR line Products
Max
. Are
al D
ensi
ty (G
bit/i
n2 )
Availability Year
Demos:102 Gbpsi111 Gbpsi
Products:up to 69.8 Gbpsi80GB/3.5”Platter40GB/2.5”Platter
From: Deiter Weller, Mar 2003 Seagate Technology
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 9
Areal Density Perspective
From: Amit Itagi, September 2003 Carnegie Mellon University
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 10
From: Deiter Weller, Mar 2004 Seagate Technology
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 11
Areal Density Trends
0.000
0.001
0.010
0.100
1.000
10.000
100.000
1970 1980 1990 2000 2010 2020Year
Gb/in2
Oxide Media / Ferrite Based
MP Media /FullThin Film Heads
(Thin Film Media/ GMR Heads)
INSIC Roadmaps 1998
MP Limit
trends.xls
2001
1
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 12
Volumetric Density Trend
0.1
1
10
100
1000
10000
100000
1970 1980 1990 2000 2010 2020Year
Gb/in3
Volumetric Density69% CAG60% CAG14% CAG10TB Cart
1 Tb/in3
10 TB Cart.
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 13
Storage Subsystem End-User Price TrendsUseable Capacity; Mean and Range
$0.01
$0.10
$1.00
$10.00
$100.00
$1,000.00
$10,000.00
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
End
Use
r Pric
e ($
/GB
)
Tape lib. (1/2" mainframe; -36%)
Tape Library (L550/8LTO)
Open RAID 5 (>2TB; -42%)
S390 RAID 1 (>2TB; -50%)
ATA RAID 5 (>2TB; -33%)ATA RAID 5 (<2TB; -33%)
Open RAID 5(<2TB; -42%)
S390 RAID 1 (<2TB; -50%)
Pricing range = 3 standard deviations; normal distribution
Source: IDC, Dataquest, Freeman, StorageTek
ATA RAID 5 as tape (>2TB; -33%)1/2" tape media (ASP)
DLT/LTO media (ASP; -25%)
NGD libraryTape media min.(OEM; -25%)
Tape lib. (DLT/LTO>40; -40%)
Canister ATA RAID 5 (50% margin)
StorageTek Secret
Tape library & media compressed 2XRAID 1 penalty: 100%RAID 5 penalty: 20%RAID 6 penalty: 0%
2002 2006 CAER Ratio of S390 RAID 1 (>2TB) to tape library (DLT/LTO; >40 carts): 47 16 - 23%Ratio of ATA RAID 5 (>2TB) to tape library (DLT/LTO; >40 carts): 8 9 3%
Published: 1/28/2003
ATA disk systems
disk systems
Tape systems
STK Tape Library
ATA disk systems
Tape-disk price convergence stabilized
Proprietary
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 14
Disk hardware costs 10X nearline tape per gigabyte
0.1
1
10
100
2004 2005 2006 2007
$/G
igab
yte
DiskNearline tape
10x
Notes:Disk and tape are an entire market averageTape includes library, drives and mediaTape assumes 2X compression
-35% erosion rate
-35% unit price erosion rate combined with a 53% unitshipped growth rate results in flat total market revenue
Source: STK analysis sourced f rom IDC, Dataquest, Meta, Horison
(Slide shown at DLSS Feb 2004 by Bob Raymond)
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 15
Capacities and Data Rates
8εNbLCapacity =
8εnbVDataRate =
N = number of tracks, b = bit density, L = length of tape,
ε = efficiency, n =number of channels, V = tape speed
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 16
Today….
System STK SDLT LTO -2 IBMT9940B 320 3592
Capacity (TB) 0.20 0.16 0.20 0.30Data Rate (MB/s) 30 16 29 40No. of // Data Channels, n 16 8 8 8Tape Width (mm), W 12.7 12.7 12.7 12.7Tape Length (m), L 648 550 584 580No. of Tracks, N 576 448 512 512TPI 1,411 1,097 1,232 1,233Trk. Pitch (microns) 18.0 23.1 20.6 20.6kBPI, b 157 191 183 277Tape Speed (m/s), v 3.4 2.9 5.4 4.8Areal Density (Gb/sq.in) 0.22 0.21 0.23 0.34Volumetric Density (Tb/sq.in) 0.48 0.41 0.48 0.78
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 17
Terabyte Operating Points½"wide tape, 3480/9940 form factor
Capacity (TB) 0.2 0.5 1 5 10 10Data Rate (MB/sec) 30 120 200 300 500 1000No. of Pll Data Channels, n 16 32 32 32 32 64No. of Data Tracks, N 576 768 1152 4750 4140 4140Trk. Pitch (microns) 18.0 14.0 9.3 2.3 2.6 2.6Channel Pitch, c p (microns) 326 164 164 82 82 82Rd. Track Width (microns) 9.0 7.0 4.7 1.1 1.3 1.3Tape Speed, v (m/s) 3.4 4.8 6.0 9.0 8.9 9.0Bit Density, b (kbpi) 159 217 279 298 500 496Track Density (tpi) 1409 1812 2719 11211 9771 9771Areal Density (Gb/in2) 0.22 0.39 0.76 3.35 4.89 4.85Volumetric Density (Tb/in3) 0.48 1.27 2.50 10.70 20.00 20.00Bit Cell (nm) 160 117 91 85 51 51Bit Cell (ns) 47.1 24.4 15.2 9.5 5.7 5.7Write Eq. Pulse (nS) 18.8 9.7 6.1 3.8 2.3 2.3Tape Length (m), L 648 865 865 1000 1400 1400Write Time per Cart. (min) 114 72 87 275 338 168
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 18
Linear Density Trend
Fe2O3 650CrO2 650
MP1 1650
MP2 1850
MPX 2400
0
50
100
150
200
250
300
1970 1975 1980 1985 1990 1995 2000 2005 2010Year
kbpi
trends.xls
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 19
Recording Theory
Transition from +Mr to –Mr over a distance, a
= −
axMxM r 1tan2)(
π
21
2322
+
=δδ d
HMa
c
r
ArcTangent Transition
-100
-80
-60
-40
-20
0
20
40
60
80
100
-400 -300 -200 -100 0 100 200 300 400
x (nm)
M(x) (emu/cc)
1501005025
a
recording.xls All these parameters are scaling down
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 20
Tape Media Progression
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 21
Areal Density Limit Calculation for MP Tape
8226.28.212
5216.55.216
3210.43.220
101810171016SNR(dB)
8226.28.212
5216.55.216
3210.43.220
101810171016SNR(dB)Particle Density, p (cm-3)
8000tpi Units: Gb/in2
21
21
lim 32
=SNRptA
Note: This is for conventional MP particles. Spherical particles (e.g. Maxell Nanocap first announced at the INSIC tape meeting at StorageTek Sept 2003) and thin film disk like media extend beyond this.
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 22
Terabyte Operating Points½"wide tape, 3480/9940 form factor
Capacity (TB) 0.2 0.5 1 5 10 10Data Rate (MB/sec) 30 120 200 300 500 1000No. of Pll Data Channels, n 16 32 32 32 32 64No. of Data Tracks, N 576 768 1152 4750 4140 4140Trk. Pitch (microns) 18.0 14.0 9.3 2.3 2.6 2.6Channel Pitch, c p (microns) 326 164 164 82 82 82Rd. Track Width (microns) 9.0 7.0 4.7 1.1 1.3 1.3Tape Speed, v (m/s) 3.4 4.8 6.0 9.0 8.9 9.0Bit Density, b (kbpi) 159 217 279 298 500 496Track Density (tpi) 1409 1812 2719 11211 9771 9771Areal Density (Gb/in2) 0.22 0.39 0.76 3.35 4.89 4.85Volumetric Density (Tb/in3) 0.48 1.27 2.50 10.70 20.00 20.00Bit Cell (nm) 160 117 91 85 51 51Bit Cell (ns) 47.1 24.4 15.2 9.5 5.7 5.7Write Eq. Pulse (nS) 18.8 9.7 6.1 3.8 2.3 2.3Tape Length (m), L 648 865 865 1000 1400 1400Write Time per Cart. (min) 114 72 87 275 338 168
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 23
GMR Spin Valve Head Data on MP Tape
Recording data compared to model
10
100
1000
10000
100000
0 2000 4000 6000 8000 10000Linear Density (fr/mm)
(µVp-p)SV ModelSV DataDSMR ModelDSMR DataSAL Model
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 24
Summary
› Tape continues to lead on volumetric efficiency and $/GByte
› Medium has primary impact on the density growth–Magnetic and physical standpoint
› Head technology in good shape!
› Limit for MP tape ~10Gb/in2
(Careful!! Disk prediction in 1997 36Gb/in2)
›Tape not near any fundamental limits at this time
© Copyright 2003 Storage Technology Corporation (StorageTek) Page 25
References
› R. H. Dee, “Magnetic tape recording technology and devices”, Proc. Int’l. Non Volatile Memory Tech. Conference (INVTC), pp.55-64, (1998).
› T. Schwarz, “Magnetic Tape as the Mass Storage Medium”, IEEE-NASA MSS Conference 2000. http://romulus.gsfc.nasa.gov/msst/conf2000/VG/C04VG.PDF
› M. Leonhardt, “Future Directions for Recording Technologies”, THIC Meeting at StorageTek, July 2003. http://www.thic.org/pdf/Jul03/stk.mleonhardt.030722.pdf.
› R. H. Dee, “The challenges of magnetic recording on tape for data storage (The One Terabyte tape and beyond)”, Proc. IEEE/NASA Mass Storage Systems Conf., NASA/CP-2002-210000, pp.109-119, (April 2002).
› R. H. Dee, “Comparison of MR and GMR Spin Valve Heads for Magnetic Recording on MP Tape”, IEEE Trans. Magn. vol.38, pp1922-1924 (2002).
› Dianne McAdam “Debunking the 7 myths of tape” , Data Mobility Group (Feb 2003). http://www.datamobilitygroup.com/
› NIST/ATP Multi-Terabyte Storage http://jazz.nist.gov/atpcf/prjbriefs/prjbrief.cfm?ProjectNumber=00-00-4939
› INSIC http://www.insic.org/tape.htm› Tape Technology Council http://www.tapecouncil.org/index.html