RE: birding-aus Digest, Vol 48, Issue 5

To: Pat OMalley <>
Subject: RE: birding-aus Digest, Vol 48, Issue 5
From: Dave Torr <>
Date: Wed, 3 Mar 2010 17:34:20 +1100
A bit of research shows that most people estimate that a flash memory card
should not be relied on after about 10 years. This is probably less that a
good quality CD or DVD. Of course there are many factors that change this.

On 3 March 2010 17:08, Dave Torr <> wrote:

> Flash was never designed for long term storage - all flash devices have a
> finite number of "write cycles" they can support and are vulnerable to
> radiation effects and other possible errors - the higher the capacity the
> more likely an error is. Perfectly manufactured and stored DVDs should last
> for maybe 20 years or so - note the emphasis on perfect!
> Basically everything deteriorates and as we pack more and more bits in
> smaller and smaller spaces they become more vulnerable. This site
>  some interesting comments - not sure how true they are but they are
> certainly good guidelines. And even if your chosen media lasts 50 years I
> can guarantee there will be no equipment that can read it after that time.
> Having been in IT for more than 40 years I have seen many technologies come
> and go - early disks were the size of washing machines and held a few
> megabytes.
> If you are really concerned back up to something that is a fairly new
> technology (and of good quality) - and preferably to two types of device.
> Every few years read the backups and rewrite them to new disks (or tapes or
> whatever) again of new technology. That way you may stay ahead of the game -
> assuming that the software still exists to read the data.
> Sorry to be a pessimist but you can't beat acid-free paper stored in good
> environment - and in several places.....
> On 3 March 2010 10:27, Pat OMalley <> wrote:
>> The comments on the deterioration of bird photos and records on CD and
>> DVD is depressing. What is the evidence of deterioration on flash memory
>> - is this a more promising medium?
>> Pat
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