birding-aus

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

To: Chris Sanderson <>
Subject: RE: birding-aus Digest, Vol 48, Issue 5
From: Dave Torr <>
Date: Wed, 3 Mar 2010 19:58:36 +1100
Sorry Chris - they may be shock resistant but they have limited data
retention timeframes - 10 years is reckoned to be reliable, 20 possible and
after that who know - you may get lucky....

On 3 March 2010 17:47, Chris Sanderson <> wrote:

> Hey Dave, solid state hard drives, while expensive, have a very long shelf
> life.  They are good because there are no moving parts at all, so less wear
> and tear on the parts over time.  Something to look into for archiving
> valuable data.  I saw a video of a guy throwing a laptop out of a second
> story window, retrieving the hard drive (solid state one) from the wreckage
> and plugging it into a new machine to demonstrate it still worked.  Not that
> I recommend trying that at home, but it's definitely a promising technology.
>
> This isn't the video I saw, but it gets the point across:
> http://www.youtube.com/watch?v=j4cK0L__B9U
>
> Regards,
> Chris
>
> On Wed, Mar 3, 2010 at 4:34 PM, Dave Torr <> wrote:
>
>> 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
>> >
>> http://askville.amazon.com/data-encoding-CDs-DVDs-flash-drives-deteriorate-time-media-safe-forever/AnswerViewer.do?requestId=8683861hassome
>>  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
>> >> www.birding-aus.org
>> >> birding-aus.blogspot.com
>> >>
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>> >
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