Question hdd x ssd and temperature humidity

[classicaran]

1) SSDs and flash memory need to be refreshed (rewriting all the same files) at intervals of 1 year or more to keep the data intact and free from corruption and bitrot.
Do 2.5" and 3.5" HDDs also have this problem? Even if the drive is in good health, if the data was written many years ago, are they at risk of corruption, loss of magnetism, bitrot, and other problems?
generally i acess energize my drives 1 once year more no nothiting write

2) Do 2.5" HDDs for long-term storage require specific, perfect conditions of 50% humidity and 25°C? Is oxidation and corrosion possible above that?

In My home varies in 24h 33-38C 55-66%

 

[Bot]

1) SSDs and flash memory need to be refreshed (rewriting all the same files) at intervals of 1 year or more to keep the data intact and free from corruption and bitrot.
Do 2.5" and 3.5" HDDs also have this problem? Even if the drive is in good health, if the data was written many years ago, are they at risk of corruption, loss of magnetism, bitrot, and other problems?
generally i acess energize my drives 1 once year more no nothiting write

2) Do 2.5" HDDs for long-term storage require specific, perfect conditions of 50% humidity and 25°C? Is oxidation and corrosion possible above that?

In My home varies in 24h 33-38C 55-66%

1) Data “refresh” on HDDs vs SSDs

SSDs and other flash memory really do have a data retention limit when unpowered. Over many years (especially at higher temperatures and if the drive is heavily worn), charge in the cells can drift and bits can flip. Many SSD controllers will refresh blocks automatically when the drive is powered and data is read, but an SSD left completely unpowered for many years can lose data.

For HDDs (2.5" or 3.5"):

• Magnetic data on a healthy HDD is generally more stable over long unpowered periods than flash.
• Bitrot / magnetic decay is possible in theory, but in practice:
  • Most failures over time are from mechanical issues (heads, spindle, electronics) rather than “magnetism fading”.
  • Data written years ago is usually still fine if the drive is healthy and stored reasonably.
• You don’t have the same strict “refresh every X years or data will vanish” requirement that flash has.
• However, absolutely no storage is perfect. Over many years:
  • Magnetic domains can weaken very slowly.
  • Aging of lubricants, head alignment tolerances, and other physical changes can make reads harder.

Your practice: powering the drive once a year without writing

• For HDDs, powering up once in a while is not a bad idea:
  • It can help avoid “stiction” (heads stuck to platters) and keeps the mechanics moving.
• It does not significantly “refresh” the magnetic data by itself.
• For SSDs, powering up and doing at least a full read can help, because some controllers will rewrite weak blocks in the background when errors are corrected.

If the data is important and extremely long-term (10+ years), good practice is:

• Keep at least two copies on different drives (and ideally one off-site or cloud).
• Every few years:
  • Connect the drives.
  • Run a full read of all important files and verify them with checksums (e.g. SHA-256 or PAR2 files).
  • Optionally copy the data to a new drive every ~5–7 years.

So: 2.5" and 3.5" HDDs don’t suffer from flash-style rapid charge loss, but very long-term storage without verification is still not risk-free. Your once-per-year power-up is fine; consider also reading and verifying the important files periodically.

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2) Temperature / humidity for 2.5" HDD long‑term storage

Typical HDD datasheets (both 2.5" and 3.5") specify:

• Operating temperature roughly: 0–60 °C (exact value depends on model).
• Non‑operating (storage) temperature often: –40 to ~70 °C.
• Humidity: wide range (e.g. 5–90% or 5–95%), non‑condensing.

The often-quoted “25 °C, 50% humidity” is more of an ideal archival target (slower aging) than an absolute requirement. Drives do not immediately corrode or oxidize when you go above that; they are designed for realistic environments.

Your environment: 33–38 °C, 55–66% humidity

• Those values are warmer and more humid than ideal, but still typically within the non-condensing spec of most HDDs.
• Potential effects of long-term storage at that range:
  • Slightly faster aging of mechanical parts and electronics.
  • Lubricants and plastics may age faster at 35–38 °C vs 20–25 °C.
  • Corrosion risk increases with high humidity, but with 55–66% and no condensation, it’s usually manageable.
• 2.5" vs 3.5": requirements are basically the same; 2.5" drives are often a bit more shock‑resistant but not dramatically different in terms of temperature/humidity sensitivity.

Practical recommendations for your case

• If possible, store drives in the coolest, most stable room you have (avoid attic, near roof, or direct sun–heated spots).
• Keep them in anti‑static bags inside a box to reduce dust and slow any external corrosion.
• Avoid locations where humidity can reach the condensation point (bathrooms, near windows with large temperature swings, etc.).
• Power them on and read/verify the important data every 1–2 years.
• For truly critical data, keep:
  • Multiple HDDs with the same data.
  • At least one copy on a different medium or location (e.g. another house or cloud backup).

Summary

• HDDs do not have the same strict “refresh every year or lose data” problem as SSDs, but long-term bitrot and mechanical aging are still possible.
• Your temperature/humidity (33–38 °C, 55–66%) is within normal tolerance but is warmer than ideal for very long storage; cooler and stable is better if you can manage it.
• The most important protection is multiple copies of your data and periodic verification, not relying on a single drive stored for many years.

 

[Parkinsond]

SSDs and flash memory need to be refreshed (rewriting all the same files) at intervals of 1 year or more to keep the data intact and free from corruption and bitrot

I have read USB SSD need to be powered on at intervals (approx 6 months) to prevent data loss or corruption, but no one stated data need to be erased and re-writen at intervals.

Do 2.5" HDDs for long-term storage require specific, perfect conditions of 50% humidity and 25°C? Is oxidation and corrosion possible above that?

Yes, heat and, to lesser extent, humidity can shorten the life span of HDD.

 

[stonjean633]

I have not played my PS4 for a year plus now. Still the SSD contains the data from last year.

This seperate the myths and theories from facts and real world experience.

 

[Sorrento]

I do keep a HD with most of my data & all of my music/photographs as well as here, in another house, though in a nuclear hit the probability is both houses would be destroyed, though if that occurs my HD's will be the least of my problems, as the houses are closeish.

I found some USB sticks in my garage last week where its subzero & 40+c at different times, nothing important on them but the data was perfect