Table of Contents
SSD lifespan (TBW value)
TBW rating for client SSDs is based on 1-year data retention at 30C as per JEDEC#218 specifications
| Usage | Power-on | Power-off (retention) |
|---|---|---|
| Client | 40°C 8hrs/day | 30°C 1year |
| Enterprise | 55°C 24hrs/day | 40°C 3mon |
Datacenter specifications for NVMe
Cell info
| SLC | MLC | 3D MLC V-NAND | 3D TLC V-NAND | 3D QLC | |
|---|---|---|---|---|---|
| Bits per cell | 1 | 2 | 2 | 3 | 4 |
| approx. P/E Cycles | 100000 | 3000-10000 | 6000 | 2000 | 500 |
Available Reserved Space/Block Count - total reserved space for remapping bad blocks.
Remark:
256GB MLC
256GB * 3000 = 750 TB total transfer (728 TB - 1200 TB in real life)
256GB TLC
256GB * 1000 = 250 TB total transfer (300-800 TB in real life)
Wear Leveling - Dynamic, Static
Initial Bad Blocks
Later Bad Blocks - Bad blocks that are developed during the lifespan of the flash
Tested SSD
| Name | Cell Type | Capacity | Data written |
|---|---|---|---|
| SanDisk SDSSDH2064G | MLC | 64 GB | 170 TB |
| Intel SSD 520 | MLC | 60 GB | 181 TB |
| Samsung 840 | TLC | 120 GB | 331 TB |
| Samsung 840 | TLC | 250 GB | 760 TB |
100 – ( 100 * Average Erase Count / NAND max PE)
source 3DNews.ru