Lifetime of a Blu-ray Disc

[thunderhawk]

Well, I've heard that CD-R are loosing data after only 5 years!
Now, I'd like to know how long DVD-R / DVD+R can hold their data and how long the Blu-ray Media will hold their data because, I don't want to copy my entire collection of CD's / DVD's every year! :?

[zombie]

I've heard that CD-R are loosing data after only 5 years!

Where have you heard this? I save many CD-Rs from several years ago and of the ones I've played recently I've had zero playback problems.

[thunderhawk]

Well, I've heard it from ppl who bought their digital camera 6 years ago, burnt their pictures on a CD-R (I think it probably was alminium, the recording layer, but I'm not sure) and they lost their pictures...
I've heard on the site of Sony that Blu-ray Disc will hold its data for 50 years, however, they also said a CD-R would hold its data for 100 years and its just 5 anymore! :? So, whats their "real" lifetime??

[timoshenko]

As I know, the CD-R have many type of dyes.
The different dyes got the different lifetime.
However, general CD-R always have more than twenty years lifetime.

[Blu-Wave]

CD Lifetimes

Based upon extensive tests, Kodak predicts that the lifetime of its photo CD and rewritable CD media with the Infoguard protection system should be 100 years or more under normal storage conditions in an office or home. The best estimate of data life under controlled conditions (temperature, relative humidity, etc.) is 217 years.

However, higher ambient temperatures may reduce lifetime, and poor recording or playback equipment can drastically reduce the apparent lifetime of the media – with the extreme of a broken recorder producing unreadable discs with a lifetime of 0. The cleaner the recording and lower the jitter rate during writing the easier it is to read the data off the disc and so the longer the disc is likely to remain readable. Recording important data at the lowest speed possible tends to produce higher quality recordings – an important consideration for archive material. :roll:


DVD Lifetimes

Based upon similar tests to Kodak, Verbatim projects the archival life of its DVD+R and DVD-R general media as more than 100 years, whilst DVD+RW and DVD-RW are projected at more than 50 years. However, this has a number of caveats, including the requirement that there is no corrosive gas in the air, that the temperature is kept constant at 25 degrees Celsius plus or minus 2 and that the relative humidity is held at 55% plus or minus 5%. :shock:

Other conditions required to ensure the projected lifetime include:
• A writer with normal performance records data
• There are no scratches or finger prints on the media surface
• Media is stored in the jewel case
• Media is not exposed to direct sunlight or any other source of UV light


BD Lifetimes

Less information is currently available about BD lifetimes. However, that which is available includes it being described as satisfactory, and more than 50 years. However the lifetime quoted for the R and RW versions of the professional version of BD, the Professional Disc for Data [PDD] are currently more than 30 years. One feature of BD designed to reduce the risk of losing data is that the table of contents and indexing information is duplicated at various locations on the disc, so damage to one system area does not necessarily prevent the data on the disc from being accessed.

Things which can affect the lifetime of a disc include high temperatures, high humidity, chemicals in the atmosphere, thermal cycling – such as hot sun during the day, cold at night, mechanical wear – for example, the head hitting the disc, the disc being left out of its caddy, and use of lower quality media.

Important data should be copied, backed up and archived at a different site, and tested periodically for readability. Some early CD players had error correction and concealment meters, which showed up any problems with discs/drives, etc.. If a BD machine kept a record of the quality of each disc it used, measuring the error rate off disc, any deterioration could be monitored and, through extrapolation (assuming kept in the same environment) the machine could request the disc back for testing, and ultimately recommend backing up the data when the degradation becomes too high. Machines such as LG’s XBD420 combined BD recorder and 200GB hard drive could even automatically backup for you – copying the data off the degrading disc on to the hard drive and then making a copy on new media. Such a function would be very valuable people who value their data in general and for archivists in particular.

As well as measuring the read/write performance of the disc, disc and lens cleaning operations could be recommended and scheduled as required and, in future, optimum write speeds for archival. In this way, you could both maximise the quality of recordings for archival and minimise the risk of losing important data – potentially a major marketing advantage.


As far as the Will it stop? question is concerned, dual-layer 50GB BDs and 1920 by 1080 pixel high definition video are only the start, but just as a dual-layer 50GB BD recorder can play single layer 27GB discs, future 100, 200 and 400GB BD recorders will be able to play all the legacy versions, and 1TB and beyond holographic media using Blu-ray technology will do more than scratch the surface, instead exploiting the wave properties of the 405nm blue-violet laser to support much higher capacity and bandwidth. See the Blu-ray and Holographic Data Storage: 1TB and Beyond… posting at http://blu-raytalk.com/forums/viewfo...902934491aa7ab for more details.

In audio too, SACD and DVDA 5.1 are all very well, as is 6, 7, and 8.1, but these all produce a ring of sound rather than a true three-dimensional Acoustic Holodeck [AH], as briefly discussed in the Suspend Disbelief posting at http://www.blu-raytalk.com/forums/vi...ays=0&start=50 and at other websites in 2003.

Although a terabyte might seem like a large amount of data now, 10 megabytes was a lot just twenty years ago, and archival sites are now dealing in petabytes (roughly a thousand terabytes or a million gigabytes). Microsoft Word doesn’t even recognise the word petabyte yet, but then again, as Bill Gates said all those years ago, no-one will ever need more than 640kB of RAM. ops:

NHK, who started working with Sony on the next generation high definition television system forty years ago, which resulted in the 2 Megapixel 1920 by 1080 p24 resolution HDTV standard we have today, has been working on the next generation after HDTV, the 33 Megapixel 7680 by 4320 pixel p60 resolution Ultra High Definition Video [UHDV] system. With image quality so good that it is almost like being there, well engineered UHDV should be virtually a digital version of IMAX, but one which could be in a home near you - but not any time soon. :?

It is proposed that the 33 million pixels of UHDV are accompanied by a 22.2 channel audio system (10 speakers at ear level, 9 above and 3 below, with another two for low frequency effects). A 1TB drive can hold around 5 minutes of uncompressed video, with a data rate of about 26Gbps. However, future video compression technology which fully exploits the entropic characteristics of ultra high definition video could allow around two hours to be stored on a 200GB, 288Mbps drive – easily within the BD roadmap for the next five years (although the codecs to support it might be another matter)

[thunderhawk]

Nice post Blu-wave :wink: