cdfreaks.com reports on a study by the Dutch magazine, PC-Active, involving tests on 30 separate brands of recordable CDs to ascertain whether data and audio tracks saved on the disks was still readable after a 20 month period. The very bad news was that despite marketing indicating data is stable for up to ten years, many brands cannot be read less than two years after they are recorded.
Back up an old CD to a new CD after 2 years of use.
Industry analysts report that the average lifespan of a computer hard drive is 600,000 hours or 3.1 years.
Back up an old hard drive to a new storage medium after 3 years of use.