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Thanks to Joe and Steve for making two important points.

For DVDs, I think the ONLY use to consider is ISO/Joliet file 
structures. NOT DVD-A.

I urge all my clients who receive DVDs to consider them in need of 
refresh after a relatively short period of time and that they need 
monitoring with the best solution being copying them into a digital 
archive. More on that subject in the not-too-distant future, I hope.

Cheers,

Richard

At 10:13 AM 4/26/2006, Steven Smolian wrote:
>My previously unmade point exactly.  I couldn't come up with less 
>than a too-unwordy explanation, but, Joe, your succinctness works perfectly.
>
>So, if I read the tea interleaves correctly, it's one MAM gold, two 
>MAM golds if a backup is required.
>
>The issue of gold DVDs arose.  I understood that the chemistry was 
>different from CDs and wonder if the former are effective for long 
>term storage. There being no actual standard for audio DVDs is 
>unsettling as well. Any tests?   Looking 25 years into the future, 
>will there be a problem getting them to play back?
>
>Someone wrote to the effect that test results from a manufacturer 
>are only advertising.  I admit they are advertising, but perhaps not 
>only.  It gives a starting place to confirm, adjust or disprove the 
>science rather than leaving a blank, "I wish we had data" void.
>
>Kodak published their tests rather than the results only.  So, if I 
>recall, did Mitsui.  TY, on the otherhand, made claims without such 
>publically avaliable back-up.  I spoke to them at the time the ealy 
>ads apperared, and was told that, since there were no testing 
>standards, they chose those that made their product look best.
>
>NIST's report on CDs gives much more conservative numbers for CD 
>longevity, even for gold ones, but the gold was vastly superior to 
>everything else. Since they never mention actual manufacturers, it 
>took much deep thought to come up the the winner's brand name in a 
>field of one.
>
>Short of having a reliable server system continually refreshing the 
>data it holds as it circulates among drives, gold CDs are the 44.1 
>answer.  Long term storage of files with higher rates on finite 
>objects is still unsettled, but  the feelgood solution seems to be 
>gold DVDs.  Until serious testing of the latter, they are feelgood 
>only and should by no means be considered a standard.
>
>Does that express the group's current state of mind on this thread?
>
>Steve Smolian
>----- Original Message ----- From: <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Wednesday, April 26, 2006 8:47 AM
>Subject: Re: [ARSCLIST] TY vs Mitsui
>
>
>>How much of an error rate difference are we talking about?
>>
>>For sure, when you burn a disc, you want a low error rate and no E22 and
>>E32 errors. However, all other things being equal if we are talking about
>>BLER of 0.5 versus BLER 3.0, this is not an issue.
>>
>>I have burned a large variety of discs on different burners and different
>>speeds for the research I have performed. The TY/cyanine does tend to
>>produce a BLER <1 on many occasions. The Mitsui/MAM can attain this, but
>>the BLER is usually slightly higher (in the 2 to 3 range).
>>
>>That being said, gold metal layer will not corrode, silver alloy will.
>>Phthalocyanine dye is very stable to light, heat, RH and cyanine is not.
>>These points are not theoretical.
>>
>>So, as Jerry briefly pointed out as well, here is a basic example:
>>
>>Disc A (gold metal/phthalocyanine): Initial Bler = 10.0
>>Disc B (silver metal/cyanine): Initial Bler =0.2
>>
>>Disc A is very stable and over 10 years does not change. However, Disc B is
>>less stable and does change over the 10 years due to exposure to one or all
>>of the following: light, elevated temperature and relative humidity, high
>>levels of pollutants from the atmosphere, or exposure from aggressive agent
>>from poor storage enclosures.
>>
>>After ten years you have:
>>
>>Disc A (gold metal/phthalocyanine): Ten year Bler = 10.8
>>Disc B (silver metal/cyanine): Ten year Bler =100.0
>>
>>Where would you rather be?
>>
>>Joe
>>
>>
>>--
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>
>
>

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