Component Feature
- 8GB eMCP, TLC
- Controller : VPX
- SS
Failure Symptom
- Can not perform the emmc command “CMD23”
Failure procedure
- Known data write
- ( random write 4K x 3500 times Sleep Resume) x 50K times
- UECC check
- Sequential write
Cause
- was caused by EOL ( End of Life)
- was caused by frequently Random Write
- was caused by frequently MetaData Update
SS Quality Criteria
Test Pattern of DWL @ Samsung(Write Amount Ratio)
| Classification | Chunk Size | Write Amount Ratio |
|---|---|---|
| Random Write | 4K/8K | 5% |
| Seq Write | 16K/32K~4M | 35% |
| Download | 4M | 60% |
WAI(Wear Acceleration Index) – Index which indicate Meta lifespan by host write amount
| item | WAI with Samsung TBW Pattern | WAI with 4K Random Write Pattern |
|---|---|---|
| SLC WAI | 0.28 | 22.96 |