We wish to expose a marketing myth regarding defragmentation of Solid State Drives. The manufacturers of these drives allege that they are so fast that an SSD should never be defragmented because it will reduce the lifespan of an SSD. We ran some scenarios to put some concreteness to these claims and arrived at the following conclusions:
Assumptions:
- Documents: Up to 10 files per day, each under 20 MB. Let’s take the upper limit: 10 × 20 MB = 200 MB/day.
- Cached Pages: Small HTTP documents, negligible in size, rarely fragment. Even generously, let’s estimate this at 50 MB/day, though likely much smaller.
- Total data written daily = 200 MB (documents) + 50 MB (cache) = 250 MB/day.
Worst-Case Scenario:
Let’s assume that all 250 MB/day fragments (though realistically, much less would actually fragment):
- Fragmentation leads to defragmentation that rewrites these 250 MB.
So, the defragmentation-related data written per day = 250 MB × 2 = 500 MB/day.
TBW and Wear Analysis:
Convert to yearly data for perspective:
- 500 MB/day × 5 days/week × 52 weeks/year = 130,000 MB/year, or 130 GB/year.
- For an SSD rated at 600 TBW (that is TerraByte Written, a measure of longevity):
- 130 GB/year = 0.13 TB/year.
- Percentage of TBW consumed annually: approx 0.022%
Adjusted Realistic Estimate:
Given the point that both small files (documents) and cached pages rarely fragment, let’s refine the estimate further by reducing fragmentation rates:
- Assuming only 10% of the 250 MB/day fragments = 25 MB/day fragmented.
- Defragmentation writes: 25 MB × 2 = 50 MB/day.
- Over a year: 50 MB/day × 5 days/week × 52 weeks/year = ~13 GB/year.
- 13 GB/year = 0.013 TB/year, consuming 0.0022% of the 600 TBW annually.
Final Conclusion:
Even with the worst-case scenario (500 MB/day), the impact on SSD lifespan is minimal at just 0.022% annually. The more realistic fragmentation pattern (50 MB/day due to only 10% of data fragmenting) lowers this even further to a negligible 0.0022% per year. This strongly supports the argument: enabling daily defragmentation in Windows 10 would have a virtually insignificant impact on SSD lifespan.
Additionally, the rare instances of large files fragmenting could be worth occasional defragmentation to ensure smoother performance.
Brand | 500/512GB | Longevity (In Use) | 1TB | Longevity (In Use) | 2TB | Longevity (In Use) | Overall Longevity (Unpowered) |
---|---|---|---|---|---|---|---|
Samsung SSD | ~300 TBW | 5–8 yrs | ~600 TBW | 6–10 yrs | ~1,200 TBW | 7–12 yrs | See footnote [1] |
WD SSD | ~300 TBW | 5–8 yrs | ~600 TBW | 6–10 yrs | ~1,200 TBW | 7–12 yrs | See footnote [1] |
Crucial SSD | ~180 TBW | 4–7 yrs | ~360 TBW | 5–8 yrs | ~720 TBW | 6–10 yrs | See footnote [1] |
Kingston SSD | ~300 TBW | 5–8 yrs | ~600 TBW | 6–10 yrs | ~1,200 TBW | 7–12 yrs | See footnote [1] |
ADATA SSD | ~320 TBW | 5–8 yrs | ~640 TBW | 6–11 yrs | ~1,280 TBW | 7–13 yrs | See footnote [1] |
WD HDD | ~180 TB/year | 5–10 yrs | ~300 TB/yr | 5–10 yrs | ~550 TB/yr | 5–10 yrs | 50–100+ yrs (ideal storage) |
Seagate HDD | ~180 TB/year | 5–10 yrs | ~300 TB/yr | 5–10 yrs | ~550 TB/yr | 5–10 yrs | 50–100+ yrs (ideal storage) |
Footnotes:
- SSD Longevity: SSDs have a limited number of write cycles, reflected by TBW ratings. Longevity varies by capacity, as larger drives distribute writes over more cells. In consumer-grade SSDs, unpowered data retention is generally 1–10 years, with longer retention risks due to charge dissipation in NAND cells. (That is, potential total loss of data without possible recovery.)
- HDD Longevity: While HDDs’ mechanical parts may wear out after years of regular use, their magnetic storage provides exceptional data retention longevity when stored in optimal conditions (e.g., controlled temperature, humidity). Records show data can remain intact for 50–100+ years when HDDs are properly stored and unpowered. Even if the mechanical parts such as drive motor or heads wear out, those parts can be replaced by professional data recovery services and data recovered if the platter itself is intact.