Article on data rot on CD's

From: Dwight K. Elvey <dwight.elvey_at_amd.com>
Date: Wed Jul 28 14:18:00 2004

>From: "Pete Turnbull" <pete_at_dunnington.u-net.com>
>
>On Jul 28, 12:11, Joe R. wrote:
>
>> The problem is that AFIK no one has found ANY CD disks that are
>> reliable. Several people that have been interviewed in national
>> publications explictly pointed out that they bought top quality disks
>but
>> they were still unreliable. In fact, it didn't appear that there was
>much
>> difference between the cheap ones and the expensive ones.
>
>The other day I came across a table from a report showing the relative
>longevity of data on various media (DLT, CD-R, etc) at a variety of
>temperatures and humidities. I'll try and find it again and post some
>of the results. Some of you might be shocked. For example, a CD-R
>with an expected lifetime of something like 25 years (if I'm not
>misremembering the highest figure) under ideal conditions has a
>lifetime of only several *months* at higher temperatures (upper 20s C,
>that would be 80s F) and humidity. DLTs fared much much better.
>
>I have some CDs that were bought about 8 years ago because they were
>supposedly good quality, and burned in a highly-rated burner. Out of
>the first batch of ten, 4 are now unreadable or give multiple errors.

Hi
 This would put the per unit failure higher than even floppies.
I have floppies that are in the 25 year range and still read
correctly ( not used regularly for archiving ). The only large
issue I've seen on floppies is those higher quality ones with
the liners. The adhesive used to attach the liners tended to
bleed through the liners and get on the disk. I do keep things
stored in areas that rarely see more than 75F or more than
75% humidity.
Dwight

>
>--
>Pete Peter Turnbull
> Network Manager
> University of York
>
Received on Wed Jul 28 2004 - 14:18:00 BST