Challenges and Trends of SSD Design
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Transcript of Challenges and Trends of SSD Design
Challenges & Trends ofChallenges & Trends of SSD Design
ADATA SSD Group 5/2
SSD Preference by Applications
Application Capacity Price Performance Quality Reliability SupplyApplication Capacity Price Performance Quality Reliability Supply
Channel 0% and 7% Sensitive Peak Moderate Moderate FlexibleConsumer OP Sensitive Peak Moderate Moderate Flexible
SIODM/OEM 0% OP Sensitive Peak High High ModerateODM/OEM
IPC 0% OP Moderate Moderate High Moderate Consistent
Server 7% and above Moderate Sustain High High Consistent
Agenda
Challenges of SSD Designg g– NAND Flash – Performance– O/P & Data Compression– Validation and Failure AnalysisValidation and Failure Analysis
Trends of SSD Design Trends of SSD Design– NAND Flash
PCI E– PCI-E
Confidential
Challenge of SSD DesignChallenge of SSD Design
NAND Flash
Confidential
Key Challenge for Quality SSD
Failure rates are multiplied proportionately to capacity When combined with other problems, it can easily exceed 1%When combined with other problems, it can easily exceed 1%
DPPM > 1%
~8000
500
5/26
ConfidentialConsumer-grade NAND Quality
Flash Qty Sorted Bad Blocks Identified Estimated DPPMf 128GB SSDFlash Qty Sorted Bad Blocks Identified of 128GB SSD
16,200 15 blocks in 12 Flash(uECC, High BER x 1) ~12,000 DPPM
DPPM R d dSSD
DPPM Reduced By Flash Sorting
DPPM Reduced By SSD Device Level Testing
DPPM
By SSD Device Level Testing
Target : 1000 DPPMTarget : 1000 DPPM
6/24
ConfidentialExample of Endurance Verification 2X/2Y/1X NAND
2Y/1X Lot
2Y Quality Lot
2x Quality Lot
7
Confidential
Example of Retention distribution 2Y/1X NAND
2Y/1X Lot
2Y Quality Loty
8
Confidential
Example of Cross-Temp Verification 2Y/1X NAND
2Y/1X Lot
2Y Quality Lot
9Low temp. : 0 degree, High temp. : 70 degree.
ConfidentialChallenges of Flash Package for Ultrathin
Performance requirement is high but PCB dimension is small.– TSOP is 1 channel design and hard to support high
performance & high density demand.Generic BGA is limited to 2 channel It’s hard to– Generic BGA is limited to 2 channel. It’s hard to meet high performance demand.
Pacakage Channel PerformanceBGA Write Pacakage Channel Performance
TSOP 1 60/40
LGA 2 120/40
100/132/152 Performance
SDP 10 MB/s
DDP 20 MB/sLGA 2 120/40
BGA100/132/152 2 120/40QDP 40 MB/s
ODP 40MB /s
10
BGA 272 4 240/80*10MB/s per die
ConfidentialAdvantage of 4CH Package on High Capacity SSD
mSATA‐4ch4ch flash 2 ch flashBus #1
Write P f
2 ch flashBus #2
Bus #1PerformanceHalf‐mSATA‐4ch4ch flash mSATA‐2ch2ch flash
4 ch flash
Bus #1
Bus #2
Bus #3
Bus #4Half‐mSATA‐2ch2ch flash
Bus #4
128 GB 256 GB
Ad t f 4 CH Fl h P k Advantages of 4 CH Flash Package– Higher performance of high capacity skew. – Suitable for compact PCB design
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Suitable for compact PCB design.
Confidential
Challenge of SSD DesignChallenge of SSD Design
Performance
ConfidentialPerformance Requirement of Sever SSD Most consumer SSD address “Sequential Read/Write” Server/Enterprise SSD focus on Sustained 4K R/W
and Latency
60,000
70,000
????260 MB/s
10GB Space
30 000
40,000
50,000
=????
150 MB/s
10GB Space
10,000
20,000
30,000= 85 MB/s
25 MB/sFull Space
0
5 20 35 50 65 80 95 110min
Consumer Server
ConfidentialLatency in Cache-based application
100
120
100.00%
120.00%
2500
3000Max Latency(ms)
times
40
60
80
40 00%
60.00%
80.00%
1000
1500
2000
Qos
0
20
1 1 001 2 001 3 001 4 001 5 001 6 0010.00%
20.00%
40.00%
0
500
1000
event
Qos
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1 1,001 2,001 3,001 4,001 5,001 6,0010 10 20 30 40 50 60 70 80 90 100event Max Latency(ms)
-PS : Max latency are recorded by Iometer 2010 every 15 minutes.
ConfidentialLatency in File-based application
35
40sec
25
30
20 SSD #1SSD #2SSD #3
10
15
0
5
0 200 400 600 800 1000 1200 1400 1600 1800 20000 200 400 600 800 1000 1200 1400 1600 1800 2000
Multi-tasking environment mixing R/W processes of large & small files. Latency may be up to 35 sec if controller FW is not good. Abnormal long latency causes bad user experience and the risk of failure Abnormal long latency causes bad user experience and the risk of failure.
Confidential
Challenge of SSD DesignChallenge of SSD Design
O/P, Data Compression, p
Confidential
OP - Over Provisioning
OP Usage– Buffer SpaceBuffer Space– Garbage collection– SSD controller firmware storage (small %)
-0% : 64/128/256/512 GB
-7% : 60/120/240/480 GB
– Spare blocks (small %) – Data protection (ex: LSI RAISE™)
-28%: 50/100/200/400 GB
Advantages of higher OP:– Higher write performance
OP Data
– Higher write performance – Lower “Write Amplification”– Longer Flash life (Endurance)
User Data
– Space for data protection beyond ECC
ConfidentialPerformance Comparison of OPs
IOmeter IOPS IOmeter IOPS (50% compressible)
50,000
60,000
50,000
60,000
20 000
30,000
40,000
30,000
40,000
0
10,000
20,000
10,000
20,000
0
1 26 51 76 101 126 151 176
OP 0% OP 7% OP 28%
01 26 51 76 101 126 151 176
OP 0% OP 7% OP 28%
-Higher OP has more buffer and gives better sustained performance . -With 50% compressible data(typical case), sustained performance is up to 3~5X
-PS : Data is recorded by Iometer 2010 every 5 minutes.
ConfidentialData Compression, Gives More OP Space
Data compressor provides bigger and reliable over-b gge a d e ab e o eprovisioning than the general SSD controller.
f
SSD with compressor
SSD w/o compressor
More OP gives more space for buffering and garbage collection.
Free Space (OP)Larger due to compressor
Free Space (OP)
p p
collection. If data is highly compressible,
SSD will have more OP so True Valid Data
True Valid Data
that the performance and reliability will be better.
ConfidentialData Compressor + OP improve Reliability
7.0
WAF with In-compressible data1.4
WAF with 50% Compressible data
5.0
6.0
1
1.2
2 0
3.0
4.0
0 4
0.6
0.8
0.0
1.0
2.0
0
0.2
0.4
Hi h OP l i b tt WAF d ld t d d i lif ti
1 26 51 76 101 126 151 176
OP 0% OP 7% OP 28%
1 26 51 76 101 126 151 176
OP 0% OP 7% OP 28%
-Higher OP also gives better WAF and could extend device life time. -With 50% compressible data(typical case), drive life time can be extended at least 3X.
-PS : Data is recorded by Iometer 2010 every 5 minutes.
ConfidentialData Compressor + OP improve Performance
IOPS
LSI SandForce Balanced Read/Write PerformanceBased on data entropy
Data entropy
40,000
45,000
50,000py
Compressible
30,000
35,000
15,000
20,000
25,0000-70%
5,000
10,000
0
0 10 20 30 40 50 60 70 80 90 100Random Read/Write %
10% 70% 100% Samsung 840 Samsung 840 Pro OCZ Vertex 4 OCZ Vector
100/0 90/10 80/20 70/30 60/40 50/50 40/60 30/70 20/80 10/90 0/100
Random IOPS after Random Writes SSD #1 SSD #2 SSD #4SSD #3Read/Write
10% 70% 100% Samsung 840 Samsung 840 Pro OCZ Vertex 4 OCZ VectorpreconditioningData collected using VDBench
SSD #1 SSD #2 SSD #4SSD #3
Confidential
Challenge of SSD DesignChallenge of SSD Design
ValidationFailure Analysis
ConfidentialSSD Validation & Trouble Shooting
Validation– Totally different to previous UFD, y p ,
SD, and exHDD.– Hard to cover all testing during
validation
Flash Vendorvalidation.
Trouble-Shooting– Not easy to identify failure due to
??Not easy to identify failure due to the failure can be anything, such as HW, SW, FW, Protocol, Flash
Module Hose
Controller VendorFlash……
– Need system engineering to narrow down the issue and find h
Hose
the root cause.
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ConfidentialFailure Analysis Categories
3 Analysis Categories
1 SATA Interface:
Flash2
1 SATA Interface:
a. SATA Protocol Analysis
b. Signal Integrity Analysis
SATA
b. Signal Integrity Analysis
2 SATA Controller & Power Circuit :
a Controller logging informationController Flash
1
a. Controller logging information
b. Power-on timing analysis
3 Fl h C t
Flash
PowerCircuit
3 Flash Component :
a. Uncorrectable ECC identification
b Physical address Flash testb. Physical address Flash test
c. BER analysis through tester
Confidential
Flash and SSD TrendsFlash and SSD Trends
Confidential
2X/2Y/1X/1Y NAND Trend
Spec Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Intel-L84A(20nm) 64Gbit, 8KB MP
2012 2013
Intel L84A(20nm) 64Gbit, 8KB MP
Intel-L85A(20nm) 128Gbit, 16KB ES CS
Intel-L84C(20nm) 64Gbit, 16KB ES CS
Intel-L85C(20nm) 128Gbit, 16KB ES CSIntel L85C(20nm) 128Gbit, 16KB ES CS
Micron-L83A(20nm) 32Gbit, 8KB
Micron-L84A(20nm) 64Gbit, 8KB MP
Micron-L85A(20nm) 128Gbit, 16KB ES CSMicron L85A(20nm) 128Gbit, 16KB ES CS
Micron-L84C(20nm) 64Gbit, 16KB ES CS
Micron-L85C(20nm) 128Gbit, 16KB ES CS
Hynix A-die(20nm) 64Gbit, 8KBy ( ) ,
Hynix B-die(20nm) 64Gbit, 16KB
Hynix D-die(1xnm) 64Gbit, 16KB ES CS
Hynix A-die(3D) 128Gbit, 16KB ES CSy ( ) ,
Hynix M-die(1xnm) 128Gbit, 16KB ES
Sandisk 19nm 64Gb, 16KB
Sandisk 1Ynm 64Gb, 16KB ES
26
,
Sandisk TLC1Ynm 128Gbit,8KB,4P ES
ConfidentialMLC Flash Pricing of Mainstream Capacity
$12.00
32 32 GbitGbit 64 64 GbitGbit 128 128 GbitGbit
$10.00
$6.00
$8.00
32Gbit
64Gbit
$
$4.00
64Gbit
128Gbit
$0.00
$2.00
NAND Price go uptrend from 2013/Q4 128Gbit mono-die MLC ready in 2013/Q3
Source: DRAMExchanges
27
y 1Y to begin another cycle
ConfidentialNAND Getting WorseHigher Requirement for Controller
3xnm MLC 2xnm MLC 2y/1x nm MLC 2y/1x nm TLC 3D Flash
C it 32Gbit 64Gbit 64/128Gbit 64/128Gbit ?Capacity 32Gbit 64Gbit 64/128Gbit 64/128Gbit ?
ECC 12 bit / 512 Bytes 24 bit /1024 Bytes 40 bit /1024 Bytes LDPC ?
PE 5K 1K~5K 1K~3K 500 ~ 1K ?
28
ConfidentialPerformance PCI-E SSD to the Mass Market
150018002100
3 X 3 X
600900
1200ReadWrite
SATA III bandwidth
0300
SATA 128GB PCIE 128GB SATA 256GB PCIE 256GB
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Up to 3x read performance, comparing SATA SSD
ConfidentialPCI-E SSD Plan in 2013
PCI-E SSD will be more focus from 2013/H2 Advantages :
– Bandwidth lead– Multi-lane for scalability (x2, x4, …..)
Software compatible PCI E SSDs can be built as one AHCI device– Software compatible PCI-E SSDs can be built as one AHCI device
M.2 2280M.2 2280 SFF 8639, 2.5”SFF 8639, 2.5”SATA Express, 2.5”SATA Express, 2.5”
PCI-E
ConfidentialAdvantage of ADATA SSD Solutions In-house Flash Testing Infrastructure and Component
EngineeringFlash quality management– Flash quality management
– Fast adoption of new Flash technology
Dedicated System Engineering & Validation Team to perform System Analysis: right specification targeting and quick debugging for customers’ time-to-market
D di t d HW D l t T f d i t Dedicated HW Development Team: focused in custom form-factor developments (allow ~ 6-wks lead time) and product-optimization such as EMI.p p
Provide all SSD solution for SI, ODM/OEM, IPC and Server customers
31
ConfidentialADATA SSD Solutions
Retail ConsumerS
SI/ODM/OEMS / S– 2.5” SATA
– mSATA / mSATA mini– M 2 SATA
– mSATA / mSATA mini– M.2 SATA / PCI-E
– M.2 SATA
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ConfidentialADATA SSD Solutions
IPC SATA DOM
ServerServer2 5” SATA– SATA DOM
– MO-297– mSATA / mSATA mini
– 2.5 SATA– 2.5” PCI-E
– CF / CFast
33