I've bought some memory cards for the purpose of backing up & storing my pictures and videos in case my PC's hard drive fails or the data on it becomes unreadable. The hard drive may not fail for a few years and so i'm wondering if from time to time i need to insert the memory cards back into the PC for it to somehow re-energise them or check the files on the cards for problems? I'm aware they retain data when the power is switched off, but does it need refreshing from time to time? I got wondering because of reading that hard drives need to have their data refreshed from time to time to stop data degradation, but i'm unsure if this applies to flash based storage too.

I suspect not, but actually don't really know for sure and so apologies if it seems like a bit of a dumb question. I would hate to plug the cards back in-in a few years only to find that i didn't apply standard procedures. Is there a recommended time limit before the cards should be replaced with complete new copies too?

I'm now thinking of buying a solid state drive too but would only want to turn it on once per year when i do the yearly album and movie backup. Would the same question about memory cards ect also receive the same answer when applied to SSD's too, if the SSD was left on a shelf?

I suppose my question could just be: Is it ok to leave memory cards or SSD's on the shelf for a few years at a time without ever plugging them back in?

Many thanks for any help.

  • 1
    You should always check you backups regularly, before you need them. :) – Ƭᴇcʜιᴇ007 May 10 '14 at 16:16

Ironically I just answered a very similar question a few hours ago about SSD data degradation.

Your first question: (do I need to unplug and reinsert my data drives from time to time) simply no. From a technical stand point this could only cause your OS to become confused and potentially not recognize a drive. I refer to the old saying of dont fix what isn't broken. Since your drives are working, even if you haven't accessed the data files on them in awhile then why unplug them?

Your second question: (does data degrade when a drive is left on the shelf for a few years) allow me to quote Reddit if I dare.

I conduct research on prototype hard drive media right now. The industry standard for bit lifetime is 10 years. That means that on average, a bit will take 10 years to randomly flip from a 0 to a 1. This is driven by random thermal fluctuations and can be modeled as an Arrhenius type equation. We try to engineer the energy barrier between states to be ~40kT or more. This is an active area of research as to make high density disks, the bits must be made smaller. However, the energy barrier between magnetic states is dependent on the volume of the bit. To combat this we make the magnets "harder" which means making them harder to switch from north pole up to north pole down. This however, causes problems in actually writing the data to the disk. There are many possible solutions to this problem but the current front runner is to use a laser on the spot you are writing to locally heat the bits so they can be written but when they cool down they are stable. The only effect of turning on the drive or not is warming it up. At higher temperatures the bits are less stable. Hypothetically, if you kept your drive very cold, assuming all the other electronics still worked at this temp, the data would last much longer.

If you read my other post I linked to above I can come to the safe conclusion that your data will be fine for a reasonable amount of time (think 1-4 years).


I found data to contradict some of what I said.

How long an SSD can store data without power depends on a number of factors including the number of write cycles that have been used, the type of flash memory used in the drive, the storage conditions and so on. A white paper produced by Dell in 2011 (PDF link) stated that it could be as little as three months to as much as 10 years.

Many SSD manufacturers will list data retention either as part of the specification or the warranty for their drives. The JEDEC Solid State Technology Association sets the industry standard at one year for consumer drives.

So in conclusion I would not use SSDs for long term unplugged sitting on the self data storage. Why not use regular HHDs or another form of backup? Hopefully in multiple duplicate locations.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.