Challenges and Trends of SSD Design
- 1. Challenges & Trends of SSD Design ADATA SSD Group 5/2
- 2. SSD Preference by Applications Application Capacity Price Performance Quality Reliability Supply Channel 0% and 7% Sensitive Peak Moderate Moderate Flexible Consumer OP SI ODM/OEM 0% OP Sensitive Peak High High Moderate IPC 0% OP Moderate Moderate High Moderate Consistent Server 7% and above Moderate Sustain High High Consistent
- 3. Agenda Challenges of SSD Design – NAND Flash – Performance – O/P & Data Compression – Validation and Failure Analysis Trends of SSD Design – NAND Flash – PCI-E
- 4. Confidential Challenge of SSD Design NAND Flash
- 5. Confidential Key Challenge for Quality SSD Failure rates are multiplied proportionately to capacity When combined with other problems, it can easily exceed 1% DPPM > 1% ~8000 500 5/26
- 6. Confidential Consumer-grade NAND Quality Qty Bad Estimated DPPM Flash Sorted Blocks Identified of 128GB SSD 16,200 15 blocks in 12 Flash (uECC, High BER x 1) ~12,000 DPPM DPPM R d d SSD Reduced By Flash Sorting DPPM Reduced DPPM By SSD Device Level Testing Target : 1000 DPPM 6/24
- 7. Confidential Example of Endurance Verification 2X/2Y/1X NAND 2Y/1X Lot 2Y Quality Lot 2x Quality Lot 7
- 8. Confidential Example of Retention distribution 2Y/1X NAND 2Y/1X Lot 2Y Quality Lot 8
- 9. Confidential Example of Cross-Temp Verification 2Y/1X NAND 2Y/1X Lot 2Y Quality Lot Low temp. : 0 degree, High temp. : 70 degree. 9
- 10. Confidential Challenges 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 meet high performance demand. BGA Write Pacakage Channel Performance TSOP 1 60/40 LGA 2 120/40 100/132/152 Performance SDP 10 MB/s DDP 20 MB/s BGA100/132/152 2 120/40 QDP 40 MB/s ODP 40MB /s 10 *10MB/s per die BGA 272 4 240/80
- 11. Confidential Advantage of 4CH Package on High Capacity SSD Bus #1 mSATA‐4ch flash 2 ch flash Write P f Bus #2 Performance Bus Half‐mSATA‐4ch flash mSATA‐2ch flash 4 ch flash #1 Bus #2 Bus #3 Bus Half‐mSATA‐2ch flash #4 128 GB 256 GB Advantages of 4 CH Flash Package – Higher performance of high capacity skew. – Suitable for design 11 compact PCB design.
- 12. Confidential Challenge of SSD Design Performance
- 13. Performance Requirement of Confidential Sever SSD Most consumer SSD address “Sequential Read/Write” Server/Enterprise SSD focus on Sustained 4K R/W and Latency 70,000 260 MB/s 60,000 ? Space 50,000 40,000 = 30 30,000 000 85 MB/s 20,000 = ? 10GB 150 MB/s 10,000 Full Space 25 MB/s 0 5 20 35 50 65 80 95 110 min Consumer Server
- 14. Confidential Latency in Cache-based application 120 100 120.00% 100.00% 3000 2500 Max Latency(ms) times 80 60 40 80.00% 60.00% 40 00% 2000 1500 1000 Qos 20 0 1 1 001 2 001 3 001 4 001 5 001 6 001 40.00% 20.00% 0.00% 500 0 event 14 1,001 2,001 3,001 4,001 5,001 6,001 0 10 20 30 40 50 60 70 80 90 100 Max Latency(ms) -PS : Max latency are recorded by Iometer 2010 every 15 minutes.
- 15. Confidential Latency in File-based application sec 40 35 30 25 20 SSD #1 SSD #2 SSD #3 15 10 5 0 0 200 400 600 800 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.
- 16. Confidential Challenge of SSD Design O/P, Data Compression
- 17. Confidential OP - Over Provisioning OP Usage – Buffer 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 OP Data performance – Lower “Write Amplification” – Longer Flash life (Endurance) User Data – Space for data protection beyond ECC
- 18. Confidential Performance Comparison of OPs IOmeter IOPS IOmeter IOPS (50% compressible) 60,000 50,000 60,000 50,000 40,000 30,000 20 000 40,000 30,000 20,000 10,000 0 20,000 10,000 1 26 51 76 101 126 151 176 OP 0% OP 7% OP 28% 0 1 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.
- 19. Confidential Data Compression, Gives More OP Space Data compressor provides bigger and reliable over-provisioning than the general SSD controller. f SSD with compressor SSD w/o compressor More OP gives more space for buffering and garbage collection. p p Free Space (OP) Larger due to compressor Free Space (OP) 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.
- 20. Confidential Data Compressor + OP improve Reliability 7.0 WAF with In-compressible data 1.4 WAF with 50% Compressible data 6.0 5.0 1.2 1 4.0 3.0 2 0 0.8 0.6 0 4 2.0 1.0 0.0 0.4 0.2 0 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% -Hi h Higher OP l also i gives b tt better WAF and d ld could t d extend d i device lif life ti 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.
- 21. Confidential Data Compressor + OP improve Performance IOPS LSI SandForce Balanced Read/Write Performance Based on data entropy Data entropy 50,000 45,000 40,000 py Compressible 35,000 30,000 25,000 20,000 15,000 0-70% 10,000 5,000 0 0 10 20 30 40 50 60 70 80 90 100 100/0 90/10 80/20 70/30 60/40 50/50 40/60 30/70 20/80 10/90 0/100 Random Read/Write % 10% 70% 100% Samsung 840 Samsung 840 Pro OCZ OCZ Read/Write Vertex 4 Vector Random IOPS after Random Writes SSD #1 SSD #2 SSD #3 SSD #4 preconditioning Data collected using VDBench
- 22. Confidential Challenge of SSD Design Validation Failure Analysis
- 23. Confidential SSD Validation & Trouble Shooting Validation – Totally different to previous UFD, SD, and exHDD. – Hard to cover all testing during validation Flash validation. Vendor – Not ? easy to identify failure due to the failure can be anything, such as HW, SW, FW, Protocol, Flash Trouble-Shooting Module Hose Controller Flash…… Vendor – Need system engineering to narrow down the issue and find the root cause. h 23
- 24. Confidential Failure Analysis Categories 3 Analysis Categories 1 SATA Interface: Flash 2 a. SATA Protocol Analysis Integrity SATA b. Signal Analysis 2 SATA Controller & Power Circuit : Controller Flash a 1 a. Controller logging information b. Power-on timing analysis 3 Fl h C t Flash Power Circuit Flash Component : a. Uncorrectable ECC identification b. Physical address Flash test c. BER analysis through tester
- 25. Confidential Flash and SSD Trends
- 26. Confidential 2X/2Y/1X/1Y NAND Trend 2012 2013 Spec Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Intel 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 CS Micron-L83A(20nm) 32Gbit, 8KB Micron-L84A(20nm) 64Gbit, 8KB MP Micron-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, 8KB Hynix B-die(20nm) 64Gbit, 16KB Hynix D-die(1xnm) 64Gbit, 16KB ES CS Hynix A-die(3D) 128Gbit, 16KB ES CS Hynix M-die(1xnm) 128Gbit, 16KB ES Sandisk 19nm 64Gb, 16KB Sandisk 1Ynm 64Gb, 16KB ES 26 , Sandisk TLC1Ynm 128Gbit,8KB,4P ES
- 27. Confidential MLC Flash Pricing of Mainstream Capacity $12.00 32 Gbit 64 Gbit 128 Gbit $10.00 $8.00 $6.00 32Gbit 64Gbit $4.00 $ 128Gbit 2.00 $0.00 NAND Price go uptrend from 2013/Q4 128Gbit mono-die MLC ready in 2013/Q3 Source: DRAMExchanges 27 y 1Y to begin another cycle
- 28. NAND Getting Worse Confidential Higher Requirement for Controller 3xnm MLC 2xnm MLC 2y/1x nm MLC 2y/1x nm TLC 3D Flash 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
- 29. Confidential Performance PCI-E SSD to the Mass Market 2100 1800 1500 3 X 3 X 1200 900 600 Read Write SATA III bandwidth 300 0 SATA 128GB PCIE 128GB SATA 256GB PCIE 256GB 29 Up to 3x read performance, comparing SATA SSD
- 30. Confidential PCI-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 M.2 2280 SATA Express, 2.5”” SFF 8639, 2.5” PCI-E
- 31. Confidential Advantage of ADATA SSD Solutions In-house Flash Testing Infrastructure and Component Engineering – 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 Dedicated HW Development Team: focused in custom form-factor developments (allow ~ 6-wks lead time) and product-optimization such as EMI. Provide all SSD solution for SI, ODM/OEM, IPC and Server customers 31
- 32. Confidential ADATA SSD Solutions Retail Consumer S SI/ODM/OEM – 2.5” SATA S S – mSATA / mSATA mini – M – mSATA / mSATA mini – M.2 SATA / PCI-E M.2 SATA 32
- 33. Confidential ADATA SSD Solutions IPC SATA DOM Server – 2 5” SATA – MO-297 – mSATA / mSATA mini – 2.5 – 2.5” PCI-E – CF / CFast 33