Longevity of Solid State Memory Cards?

Late last year, our house was broken into and a bunch of electronics were stolen, including the MiniDV video camera we had had since our wedding (fortunately the thief didn’t take all of our saved tapes). My video workflow over the past decade has consisted of shooting (judiciously), occassionally making a short web video, and putting the tape away in a cabinet for the archives.

When the camera was stolen, I replaced it with an HD camera that stores video data on SD cards. The usual workflow for SD-based cameras is that you extract what you need to disk when the card is full, then erase and re-use it. But I don’t always have time to do the reviewing and capturing every time, and don’t always feel comfortable erasing the card and starting over to shoot more footage. The question becomes, what is the best way to store this data long term?

I could of course buy another external hard drive dedicated to the task. They’re cheap enough, but experience teaches that disks are fallible, so then you get into the problem of having to back up what could quickly become terabytes of data.

Another solution would be to buy archival grade DVDs and copy data to them as cards fill up.

A final option would be to NOT reuse SD cards, but to replace them when full instead, and stack them in the cabinet for archival purposes just as I used to do with MiniDV tapes.

Doing some comparison shopping, it looks like the price ratio between using archival DVDs and buying new SD cards is similar enough to be neglible. The question then becomes, how do the shelf lives of these two media compare? If you search for information on the longevity of SD cards, you find lots of information about how they’re only good for a limited number of read/write operations before they start to fail… but that’s not what I’m interested in. I’m talking about writing to them once, only reading them a few times max, but storing them for years or decades. It’s surprisingly difficult to find information on how long data on an SD card will last if NOT used.

I’m confident they’d be fine for a few years. But what about 20? What about 50? (yes, I want my kid to be able to access this data when he’s grown up, hopefully without going through the hoops I recently did dealing with my dad’s 60-year-old 8- and 16-mm film stock.

Archival DVDs claim to be good for 100 years, and I’d be willing to trust that figure, or something like it, even though none of them have been around long enough for the estimate to be verified. But for convenience, I’d love to be able to skip the transfer step and just store SD cards long-term. Without information on that, I’m skittish about it.

Anyone have info on long-term shelf-life of unsed SD cards?

11 Replies to “Longevity of Solid State Memory Cards?”

  1. Two and a half hours of35mm movie film fills a 14” reel. Edited, that’s probably 4 to 5 DVTs. Maybe someone out there is like my dad and has a hundred + DVTs. That’s five +/- 14” film reels – each in its own box. Conversion to film to cover the edited DV – about $300. Equipment that plays film – used, good quality $400; New, few hundred to thousands, your choice. Storage – old-school, metal military foot locker, self-applied foam gasket (any good surplus store) $40. So, about 4-5 years of priceless memories stored safely for 30+ years (until some decent technology arrives); about $900 bucks. Don’t’ forget the anti-desiccants – the kind you get from serious camera shops, not wal-mart. Well stored film has a reliable shelf life of 50 years. As do American and Japanese made film projectors. If one has a basement, or well a sealed container, some decent fraction of that time is attainable. I know it sounds prehistoric and ungainly, but I find it fun, and it’s a proven technology. My dad and three of his friends share a projector. One of them has been a photographer for 50 years, and swears by the method for his negatives. OR …give it all up, let go, trust your memory, let technology play it’s own game in the universe and treasure what might be left over when it’s time to look for a little doo-hicky to help you remember. Some will be there, some won’t. A bit of refugee philosophy.

  2. I’ve had some disturbing experiences with allegedly archival DVDs and CDs (so-called Gold media from reputable optical media manufacturers). For example, I’ve had many of these disks, redundantly burned and verified with Roxio Toast on G5 Macs, fail to be readable with Mac Pro’s optical drives but still be readable with G5s’ optical drives. If I had been a bit less savvy, I would have freaked out, thinking I had lost the data and the media mad failed. I’ve also experienced other readability glitches between different generations of drives, i.e. burned with one generation of drive, couldn’t read with another generation. I can’t blame the optical media itself, but this made me wary of assuming that I could read files off of archival optical disks reliably whenever I needed to in the future. My home solution was to abandon optical disks and just archive multiple copies on hard drives, and copy from these drives periodically to larger capacity drives as their prices drop.

    I wouldn’t trust SD cards to be archival or, even if the data is intact on them, be readable in the future. I would copy from them onto, say, a trio of $100 1TB hard drives, store one offsite, and update these as needed until more capacious drives arrive at a low enough price point to do a forward migration. Stir every couple of years as needed. YMMV. :-)

  3. Paul, great feedback on the viability of film. A bit of extra hassle, but you’re right about proven technology and known shelf life. My biggest reservation about that is what I went through with Dad a couple of years ago when wanting to resurrect all of his old 8-mm film. He had three projectors, all broken in one way or another. It took a lot of hunting to find a replacement bulb for the one that basically worked, and the seller of that said he was almost out, no more to come. The film itself was falling apart, returning to dust. So 50 years is great, but the reliability does fade…

    Larry, interesting stuff about optical drives not being universally capable of reading discs. Not a good sign, and so much for “standards.” I’m inclined to go with a HDD based archival solution too, and commit to replicating them periodically. Easy to say now, but I can see falling off that wagon and finding a 20 year old HDD in the garage, long since failed.

    Wouldn’t surprise me if some of the longest lived of these are the copies on YouTube or personal web sites. At least you know those are being backed up on a regular basis by the datacenters they live at.

    Funny – 3,000 year old Egyptian papyrus, so delicate, still around and still readable.

  4. Funny, it would seem that the easier it has gotten to write, the harder it has gotten to actually *preserve*.

  5. Most solid state memory devices come with a 7-10 years warranty and some even boast a lifetime warranty. I use flickr to store my photographs online (less than $2 per month). But I am in the same boat when it comes to videos.

  6. Scott, I was looking for information on solid state memory devices and came across the conversation here. I am involved with Millenniata, Inc. a company that is making a new DVD technology based on a new data storage principle. Instead of storing data as a change in a chemical dye layer we store data, using the same digital characters, as a physical change to very hard inorganic materials. The DVD once written is readable in standard DVD drives and will last a very long time. In getting the product into the commercial market we have found differences in the various DVD drives, something that is addressable but it was not simple. Current discs have been tested by NIST and others and will fail very quickly.
    Henry

  7. We have been conducting accelerated live testing, both the tests of the ECMA standard and a group of more strenuous set of tests. The ECMA standard was developed with the work of the NIST and other organizations, you may know this… When we expose our disc to this set of tests all discs survive and are readable. Because the data is recorded as physical changes in a metal layer sandwiched between two layers of inorganic carbon based material. With all of this said, the current testing would indicate that the data is stable for more than 100 years.

    Henry

  8. ‘This gnarly question has posed an enigma forever, but presently has high priority because there are a number of technologies that vye for this standard. After decades of working with the possibles for an absolute answer, there seemed to be a paradox. The solid media, DVD and recent generation of metallic or bi-metal discs, could only evolve to the degree that the present technology would let them. The highest tech, helical biased, data tape was still being improved and evaluated. So that not only according to
    individual use, but from comparing results using input from The Internet, the maximum stability and longevity of archival media was from the use of highest quality data transfer tape. Maybe that translates as a ‘Bang-For-Buck’ perspective, but that refers to the footage being there for your children and grand-children to edit, if you couldn’t get to doing that. Another advantage to using this method has been that some of the data transfer tapes were configured for a particular tape machine, say beta-max, vhs or even hi-8 and subsequently may be used DIRECTLY to keep the data on. If you want to duplicate that with a HDD, then that’s certainly possible. The concluding twist being that recently there have been some editing software for consumers that convert the ‘other’ resolutions to 1080i or 1080p, so that you could keep using your beta-max cam and lenses, then convert from the data transfer tapes to a metal media as a ‘1080i or p format.’

  9. I think that some recording drives go weak in some way, so their discs are hard to read in other drives.

    There are of course other problems, such as the different flavours of recording software to use -RW media like it were a giant floppy (InCD and such software, a real Tower of Babel of incompatibility), multi-session regular CDs whose last TOC does not show early sessions (you can get SW to read them), and some different versions of video CDs.

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