Mudcat Café message #702873 The Mudcat Café TM
Thread #47161   Message #702873
Posted By: treewind
02-May-02 - 10:29 AM
Thread Name: TECH: How long do CDRs last?
Subject: RE: TECH: How long do CDRs last?
There is some more and possibly the most reliabe and up to date information on the CD-Recordable FAQ web pages.

The ability to keep the data does not depend on the power of the CDR recorder's laser. The CDR preamble (data already burnt in at the start of the groove) actually indicates a recommended writing power, which depends on the dye used and manufacturing process, and the recorder (if it's nay good at all) adjusts itself as directed. Too much would fail just as badly as too little.

Anahata

P.S. here's some of the CDR FAQ on this subject:

The manufacturers claim 75 years (cyanine dye, used in "green" discs), 100 years (phthalocyanine dye, used in "gold" discs), or even 200 years ("advanced" phthalocyanine dye, used in "platinum" discs) once the disc has been written. The shelf life of an unrecorded disc has been estimated at between 5 and 10 years. There is no standard agreed-upon way to test discs for lifetime viability. Accelerated aging tests have been done, but they may not provide a meaningful analogue to real-world aging.

Exposing the disc to excessive heat, humidity, or to direct sunlight will greatly reduce the lifetime. In general, CD-Rs are far less tolerant of environmental conditions than pressed CDs, and should be treated with greater care. The easiest way to make a CD-R unusable is to scratch the top surface. Find a CD-R you don't want anymore, and try to scratch the top (label side) with your fingernail, a ballpoint pen, a paper clip, and anything else you have handy. The results may surprise you.

Keep them in a cool, dark, dry place, and they will probably live longer than you do (emphasis on "probably"). Some newsgroup reports have complained of discs becoming unreadable in as little as three years, but without knowing how the discs were handled and stored such anecdotes are useless. Try to keep a little perspective on the situation: a disc that degrades very little over 100 years is useless if it can't be read in your CD-ROM drive today.

One user reported that very inexpensive CD-Rs deteriorated in a mere six weeks, despite careful storage. Some discs are better than others.

By some estimates, pressed CD-ROMs may only last for 10 to 25 years, because the aluminum reflective layer starts to corrode after a while.