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

https://www.opencompute.org/documents/datacenter-nvme-ssd-specification-v2-0r21-pdf

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