Posted by L Alpert on 12/31/07 13:22

JR wrote:
> "L Alpert" <alpertl@xxgmail.com> wrote in message
> news:j5Odj.184$jJ5.15@newssvr11.news.prodigy.net...
>> Big Daddy wrote:
>>> "Leroy" <we3v543erferet567y6@swe.com> wrote in message
>>> news:Xkwdj.37761$DP1.5659@pd7urf2no...
>>>> He's right.
>>>
>>> no, he's not.
>>>
>>>> The data is very close to the top of the disk so they HAD to put an
>>>> extra coating on it.
>>>
>>> Has nothing to do with "rotting". The disks are not "prone" to
>>> rotting.
>>
>> Rotting? Polycarbonate "rotting"? Never heard of this. There can
>> be damage due to UV exposure, though if this is a problem for a
>> specific device, there can be UV inhibitors used in the base polymer.
>>
>> The disc itself should outlive the useful life of the technology.
>
> Thats what they said about DVD and CD's and they are rotting all over
> the place now.
>
> Bitrot is another name for it. more common on burned Cd's DVD's but
> still were not getting the "lifetime" of safe starage like they
> claimed. more like 6-15 years.

"Bit-rot", is not the same as "rot". The former implies usefulness of the
device that cannot be known until the device is placed in service, the
latter implies a physical condition that can be visualized.

I cannot say that I have seen this phenomenon of bit-rot myself, and I have
discs that are quite old that I still use, a few of them >15 years (I even
have some 5 1/4" floppies that work), though I wouldn't discount the
phenomenon.

2nd tier low cost vendors are very cost conscious, and may use other 2nd or
3rd tier vendors for the raw polymers to manufacture the media, as the resin
is the highest manufacturing cost. A few cents per pound can mean a much
higher gross margin when using millions of pounds, and could be a
contributing factor (I see this in other segments of the polymer industry
all the time).

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