SSD Lifespan Explained: How to Estimate and Monitor Your Drive's Health

Due to their increased speed and dependability, SSDs (Solid State Drives) have supplanted conventional hard drives.  However, because of how they store data, SSDs have a limited lifespan.  Every time you write data to an SSD, it somewhat wears out its memory cells.  Thankfully, manufacturers provide ratings to determine how long an SSD will endure.  You may also check its health using programs like CrystalDiskInfo.

Why Do SSDs Wear Out?

SSDs store data in flash memory cells. Each time you write data, the cells degrade a little. To prevent fast wear, SSDs use wear leveling, which spreads out data evenly across all cells. Despite this, SSDs still have a limit on how much data they can handle before performance issues begin.

How to Estimate Your SSD’s Life?

1. Using TBW (Terabytes Written)

TBW (Terabytes Written) refers to how much data can be written to an SSD before it starts having problems. For example:

You have a Samsung 970 EVO Plus 1TB – 600 TBW. If you write 50GB per day, a 600 TBW SSD would last 12,000 days (600,000 GB ÷ 50GB per day) or about 32 years.

2. Using CrystalDiskInfo

You can check your SSD's health using CrystalDiskInfo, a free tool that provides information about drive usage.

Steps to check your SSD health:

• Download & install CrystalDiskInfo.
• Open the program and find the Total Host Writes. (data written so far)
• Compare with TBW rating of your SSD.

Calculate usage percentage:

Example: If your Crucial BX500 1TB has a TBW of 360TB
And CrystalDiskInfo shows 72TB written
Formula: (Total Host Writes ÷ TBW) × 100
(72 ÷ 360) × 100 = 20% of lifespan used

How Likely is Your SSD to Fail? (MTBF Calculation)

Another way to predict SSD failure is using MTBF (Mean Time Between Failures). This measures the average time before an SSD fails.

Example: The WD Blue SN570 1TB has an MTBF of 1.5 million hours
MTBF applies to a group of 1,000 SSDs used for 8 hours daily
Formula: MTBF ÷ (8 hours × 1,000 SSDs)
(1,500,000 ÷ 8,000) = 187.5 days per failure

This means that, for every 1,000 SSDs, one might fail every 187.5 days.
To calculate the yearly failure rate:

(1 failure per 187.5 days) × (365 days ÷ 187.5 days) = 1.95 failures per year per 1,000 SSDs
Failure rate = 1.95 ÷ 1,000 = 0.195% per year

Most SSDs last much longer than their estimated lifespan. If you monitor your SSD’s TBW and MTBF ratings, you can predict its health and replace it before it fails. Regular backups are always recommended, but with proper care, your SSD should last many years without issues.

This Article is based on information from XDA