SDHC long term storage reliability

[Simon Wyndham]

Does anyone know about the storage reliability of SDHC cards compared to, say, backing up to Blu-Ray or DVD?

I am going to trial using SDHC cards like I used to use XDCAM discs. Buy them and keep the footage on the shelf, or reuse when the footage isn't needed anymore.

This would eliminate the need for cumbersome backup to Blu-Ray and other discs, and also turn the recording medium into a disposable rather than an asset. They are so cheap now that it would be easy to get two cards and back up the footage that way.

Sandisk have already launched a write once version of SD that is said to have a storage life of 100 years. So I wonder if standard SD and SDHC is pretty good anyway. If normal SDHC can match the 50 years predicted lifespan of XDCAM disc then it will still be better than going to DVD etc.

[Peter Kraft]

Simon, very good question. Of course, nobody knows for sure and all life spans are estimates not by guessing but based on lab tests. Artifical ageing is the key word in that context. The main question however, is, are these estimates "conservative" (rather shorter life span) than not.
With the current pace in development I'd say 10 years is already good, 20 years would be marvelous. Everyhing beyond is beyond my imagination, because can I hope to be still alive then? So this question at a certain point turns more into a philosophical one then a technical.

Nevertheless - very good question. Thank you.

[Jay Gladwell]

Simon, SanDisk is going to release (in 2009) a new WORM card with enough capacity for video storage. The shelf life is reported to be 100 years. They are supposed to make the announcement the first part of '09, whatever that means.

No doubt it will be expensive.

I, for one, am lookig forward to it.

Check out this thread:
http://www.dvinfo.net/conf/sony-xdca...deo-files.html

[Alastair Traill]

The storage life of the media is one thing, but whether the equipment to play the media still exists in ten, twenty, thirty years time or whenever is another.
If the playback equipment still exists will the media be editable with future editing programs?

[David Heath]

Originally Posted by Simon Wyndham

Does anyone know about the storage reliability of SDHC cards compared to, say, backing up to Blu-Ray or DVD?

It's a very good question indeed, especially with SDHC costs/GB reaching near equivalence with XDCAM discs. Surely there must be a research document somewhere? Before I committed to such for long term storage, I'd like something fairly official to reassure clients with.

Originally Posted by Alastair Traill

The storage life of the media is one thing, but whether the equipment to play the media still exists in ten, twenty, thirty years time or whenever is another.

Nothing is absolute, but I'd say that an SDHC or Compact Flash card is about as good as that can get. You could store a reader along with the media, and I'd be far more confident of it working in many years time than anything with moving parts. Maybe the USB connection will be the thing that will cause the most obsolescence problems? How long will computers have that?

[Erik Phairas]

I still have memory cards for my Playstation one that are from 1995/6 and they still work.. I have carts for my Jaguar that are from 1994 that have flash memory in them that still hold high scores.

[Simon Wyndham]

I don't think that this is an issue. After all we are talking about files that can be copied faster than real time. Although it might be a pain you can still copy those files over to whatever new storage systems arrive on the scene.

But with SDHC that won't be for a long time simply because there are so many SD devices in circulation. Nothing like that ever happens over night.

You could store a reader along with the media, and I'd be far more confident of it working in many years time than anything with moving parts.

The other thing that is favourable is that, assuming I understand things right, SD cards do not need to keep a voltage in order to hold data. So things like voltage leaks over time leading to loss of data shouldn't be a problem.

How long will computers have that?

A loooooong time, simply because even with USB 3 there will be backwards compatibility, or adaptors to create compatibility.

[Peter Kraft]

Sandisk talks about a lifespan of 100 years. ok.

Please turn your memory 100 years backwards: 1908.

Electricity. Yes, in its infancy.

Telephone: Nope

Radio. Mr. Marconi, when did that happen first?

Airplanes. Will men ever be able to fly like a bird?

Computers. What is that?

Digital media? Even not in science fiction novels.

In 1908 my grand dad was an 8 year old boy. When he died,
he was 72. And he never understood what the Apollo landing
on the moon in 1969 really was.

So the real question here is, how long will be tools available
to read the data from the memory. And additional means to
decipher the meaning of that data, consisting of 0s and 1s.

Compare that with old papyrus fragments from ancient egypt,
some 2500 to 3000 years old. Your eyes can see the hyroglyphes
and your brains may be able to decipher their meaning.

It's the virtuality of modern digital data that makes it so
vulnerable to ageing, even more vulnerable than from the physical ageing
of the layer it is stored upon.

-end of philosophical rant.

[Alister Chapman]

The first large scale mains distribution systems started to roll out in the 1880's in the US and Germany, the telephone came into existence in 1876 with phones becoming widespread by the end of the 1880's. First true radio transmission was by Oliver Lodge in 1894. One hundred years ago they were transmitting across the atlantic.

What should be considered is how difficult it is becoming to find good Video 8 decks or betacam decks yet these are technologies that only went out of production 10 years or so ago. Whatever you use today to store your material it is likely that in less than 10 years time you will want to transfer it to something else before playback becomes problematic.

I bet 5 years ago PCMCIA users felt that was future proof. Give it another 5 years and it's going to be difficult to find a computer with a PCMCIA slot and I doubt there will be many people making adapters.

[Jay Gladwell]

Peter, Simon has already addressed your "concern."

[Simon Wyndham]

Yep. Just copy files to the new storage.

Another thing to consider is whether or not people in 100 years time would want to watch a video demonstrating how to use a carrot peeler from 2008 ;-)

[Peter Kraft]

Originally Posted by Simon Wyndham

Yep. Just copy files to the new storage.

Simon, with all due respect, things can be but they need not be as easy as you put them.

While you can project old 16mm b/w films from the 30s of the last century today, you'll find it difficult to read a 5,25" floppy disc from 1982 that contains a simple letter.
And given the amount of data that piles up with every new digital video project, who has the time and the money to pay for "to copy the files to a new storage".

While i can store 8mm films more than 50 year old in a dry dark cold room (less than 50% humidity), with low temperature (less than 5 degrees centigrade) and no
natural light for another 50 years, the same does not apply to digital data.
All major movie films are separated into RGB and printed to b/w films for archiving. Not the digital data they have been derived from, but simple old b/w film.

[Simon Wyndham]

While i can store 8mm films more than 50 year old in a dry dark cold room (less than 50% humidity), with low temperature (less than 5 degrees centigrade) and no
natural light for another 50 years, the same does not apply to digital data.

Yes, but one thing you are forgetting here is that we are talking about digital data. Films from 100 years ago are one thing, but here is one fundamental question. Where is the original footage with which to make a new edit of those films?

I'll tell you where. No where. It doesn't exist. So quite simply there is no parallel to the situation we find ourselves in now. But what I can say is that the situation is a lot more manageable. We have the internet so we have a lot of advanced warning about what technology is around the corner, and we can therefor prepare for it.

you'll find it difficult to read a 5,25" floppy disc from 1982 that contains a simple letter.

Difficult, NOT impossible.

You make the analogy of 5.25" diskss. Well I was using them and I managed to copy my data to 3.5" disks and then eventually hard disks. It wasn't hard. Like I said, if you keep up with technology and adapt your data there shouldn't be a problem.

Hell I can still get hold of a working ZX-81 if I wanted to! You can always get hold of old technology if there is *really* a need. But like I said, c'mon people, what is the likelyhood you will actually need *your* video in even 10 years time, let alone 25, 50 or 100!?

[Ted OMalley]

Well, I don't know about you, but I fully anticipate MY carrot peeling video to be discovered in some archive, several centuries in the future. They'll discover that my haphazard and rudimentary use of digital recording equipment and available light to be "novel" and "brilliant" and "either ahead of or behind my time" - but they won't quite be sure which.

I'm planning ahead for this, and am archiving every byte in stone with a hammer and chisel.

[Simon Wyndham]

ROTFLMFAO!

Happy Christmas Ted, you just made my night! :-)