ATTACHMENT TO COMPACT DISCS PRESENTATION.


DATA STORAGE. FOR CHELTENHAM U3A S+T.

1.  It will be a good policy not to rely on hard drives for long term storage. Some commonly used storage devices are shown below as a guide to users about what reliability of data retention can be expected.

 2.

Analogue magnetic tape - 20 years

Commercial audio CDs and movie DVDs - 25 years

CD RW and DVD RW - 7.5 years

CD-R (Cyanine and Azo dyes) - 7.5 years

CD-R (Phthalocyanine dye, silver metal layer) - 25 years

CD-R (Phthalocyanine dye, gold metal layer) - 100 years

DVD-R - 25 years

Flash - 10 years

 
4.   To maximize the life of CD-Rs they should be stored in cool dry places away from sunlight as UV exposure reduces their life. It is also recommended that one avoids writing on them with permanent markers and use specially designed paper labels.

 
5.   Professional archivists are becoming concerned about the increasing volumes of stored data and the growing reliance on electronic storage. (corruption and retrieval problems increase with time). The costs of paying for the best media are rising, even so, they believe that information will not last as long as paper records.