Ken wrote regarding '[OT] Is your oldest CD-R still readable?' on Thu, Jan 12 at 20:01:
> How old is your oldest recorded CD-R disc?

I've got CD-Rs that are darn near a decade old, and the only ones that
have failed are ones that failed right away.  As far as I've tested,
anyway. :)  I've actually got more pressed CDs (which aren't covered by
the story) where the aluminum has holes or cracks...

I did some research on this when it started making the rounds a couple
of days ago.  It seems that the CD-R geeks (I didn't know they existed
either) say that the made in Japan disks are the best, while the made
in China are the worst and the made in Taiwan disks are better than
Chinese but still not that great.  The manufacturers change around
without changing their packaging noticably, so you have to check every
time you buy.  Fuji seems to be most consistently made in the Japanese
plant, so that brand is apparently the favorite for when you can't
check the label.  Then there's the Mitsui/mam-a gold subtrate disks
with the phenylcyanine (I hope I spelled that right) chemical layer
for when you really want it to last.  You're looking at about
$2-$3/disk, but they're supposedly the ultimate for longevity.

On any disk, burning at a slower speed seems to increase the
reliability of the burn, as well.  16x is the sweet spot, where the
drives typically go to a constant linear velocity (the inside pits
pass the laser at the same speed as the outer pits) as opposed to a
constant angular velocity (rotational speed is constant, so the outer
bits pass much more quickly than the inner bits).  I've unknowingly
verified that with some cheap media I had before - the CD player in my
car wouldn't read the outer tracks it if I burned at any speed over
16x, but I could read the disk on a computer and in another car fine.
Apparantly better media would result in disks that the same car could
read when burned at 52x.

At least, that's my understanding.  Looking at the packages of disks
around me, the ones that I've had problems with are, in fact, all made
in China, while the made in Japan disks I have all worked well.  I
bought them all before I learned this much, so it's somewhat neat to
see that the seemingly random crud one finds about this kind of thing
online is actually true inthis case. :)

--Danny
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