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DVDs are worse than CDs

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"Error posting message: 441 Article rejected by Spamassassin"
said Alpine but I am not trying to spam.

I recently made a webpage, i.e.
HTTPS://Gloucester.Insomnia247.NL/media/media.HTML

I copied and pasted from it to a submission to the USENET but Spamassassin 
does not like that. So I removed parts. If you are interested, then it may 
be sensible to read this webpage instead of just these excerpts on USENET.

"Which medium is good?
An SSD (Solid-State Drive) is better than a Hard-Disk Drive (HDD). Cf. a 
webpage by excellent Adaist Jeremy Grosser's Legitimate Data Company LLC: 
HTTPS://DiskPricing.com/faq and HTTPS://WWW.StorageReview.com/ssd-vs-hdd

SSDs and internal hard disks are preferable to DVDs and CDs.

Avoid USB flash sticks and USB external hard disks. Operating systems are 
buggy and USB ports do not always remain properly powered (especially 
lapstops old computers' and notebook old computers' USB ports). Files' 
names on USB external hard disks and on USB flash sticks tend to become 
destroyed. Writing to a flash memory destroys a flash memory. Using a 
hard disk destroys a hard disk. Using a USB product destroys a USB 
product.

A DVD is worse than a CD. Cf. "There are some anecdotal reports that 
DVD±Rs have separated due to adhesive failure or that the metal layers 
have corroded due to the chemical reactivity of the adhesive. An 
accelerated aging study looking at the stability of DVD formats found 
this to be potentially an issue, at least under elevated temperature and 
RH conditions (Iraci 2011)." says 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html 
(Cf. "Newer doesn't mean better. Newer means newer!" said a physicist at 
Spain.)

HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html 
said that a gold CD-R is better than a silver(-alloy) CD-R. 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html 
gave me the impression that a "phthalocyanine" CD-R is better than an 
"azo" CD-R. The DVD+R Double Layer company that is called Verbatim 
advertises that it made a DVD+R DL with "AZO recording layers". Is "azo" 
"AZO"?

A "multi-layer format" is worse than a "single-layer recordable DVD" 
according to 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html

A gold DVD-R is less bad than a non-gold non-CD-R, according to 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html

A DVD-RW is much worse than a CD-RW, according to 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html

Do not write to a CD or a DVD or a flash medium more than a few times. 
Write to a DVD or a CD preferably approximately 1 time.

"Store the discs properly: in a standard-size jewel case without 
additional materials in the case" says 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html

A DVD+R is worse than a DVD-R according to 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html 
(Cf. "Newer doesn't mean better. Newer means newer!" said a physicist at 
Spain.)

A BD-R has "poor stability compared to" a CD or a DVD according to 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html 
(Cf. "Newer doesn't mean better. Newer means newer!" said a physicist at 
Spain.)

A CD-RW is much worse than a CD-R, according to 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html

The best technique to maintain a CD or a DVD is not clear to me.
I am a computer scientist. No lecture and no class note and no textbook 
for my computer-science degree is about CDs or DVDs. Many computers from 
my computer-science degree do not have even a CD drive. I do not know 
each thing about a CD or a DVD.

I interpret this picture of (pressed (i.e. not burnt)) orthogonal DVDs to 
show Mork & Mindy to be horizontal with a pressed "surface face down" and 
Transformers to be "vertical". (Am I mistaken?)

The DVD-R company that is called Kompact says: "store the disc in a case 
with recording surface face down."

I am having a trouble with this quoted paragraph of 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html 
- "Store discs vertically in standard-sized jewel cases. Paper or plastic 
sleeves are not recommended as they provide little physical protection, 
they may interact chemically with the disc". Do I misinterpret this 
quoted paragraph by the Canadian Conservation Institute? To me it seems 
to contradict Kompact saying: "store the disc [. . .] with recording 
surface face down." What are "jewel cases"? An Oxford dictionary failed 
to inform me. A Merriam-Webster website explains that they are plastic. 
Why are "plastic sleeves [. . .] not recommended" but "jewel cases" are 
recommended? If "plastic sleeves" and "jewel cases" are plastic, then are 
they equally dangerous of interacting "chemically with the disc" and 
scratching?

What are "standard-sized jewel cases"? Many a jewel case for a DVD is 
much bigger than a DVD as with this picture of Mork & Mindy and 
Transformers, but many a jewel case for a CD is almost as small as a CD.

HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html 
is about media which are recorded onto via lasers. Is it also applicable 
to pressed CDs; DVDs; and Blu-ray discs?

Slowly burn.
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html 
recommends to record slowly.

water
"In humid tropical climates, care must be taken to find discs that stand 
up to the weather. One user reported that the data layer on [. . .] discs 
began cracking after a couple of months in an otherwise sheltered 
environment (e.g. no direct sunlight).;" said CDRFAQ.org.

Do not permit relative humidity to be higher than 50% according to 
HTTPS://WWW.Canada.Ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/longevity-recordable-cds-dvds.html

Alas it is difficult to permanently maintain relative humidity at below 
64%! (I used to succeed at a humid place during days to reduce relative 
humidity to below 50%, but during nights relative humidity is badly big.)

"Do not leave the [grey] disc [. . .] in [. . .] excessive moisture" said 
Capcom(R) Classics Collection Vol.1 without an explanation as to what 
"excessive moisture" is.

A page for a TDK 2x DVD-RW shows"10~90%": is this a warning to stay 
within circa 10% - circa 90% relative humidity?

A page for a Verbatim 8x DVD+R DL shows"6-85%": is this a warning to stay 
within 6% - 85% relative humidity?

A page for a Verbatim CD-R shows"10-80%": is this a warning to stay 
within 10% - 80% relative humidity?

LASERs can not be maintained forever.
"Subject: [5-27] Will the laser in my drive wear out?
(2002/12/02)
Yes, eventually. Depending on a number of factors, though, it's quite 
possible that your device will suffer mechanical breakdown or simply 
become obsolete before that happens.

There are many different ways to construct a laser diode. Different 
approaches result in different wavelengths, maximum power levels, and 
lifetimes. The lifetime of a laser is usually measured as MTTF (Mean Time 
To Failure) at a particular power level and ambient temperature (e.g. 
10,000 hours at 5mW and 50 degrees Celsius).

Higher power levels mean higher heat dissipation -- the optical 
conversion efficiency of a laser diode is around 30% -- and in the 
semiconductor world, more heat usually equates to shorter lifetime. 
Recording for an hour at high speed will take a greater toll on the laser 
than playing a CD for an hour.

[. . .]

Laser diodes can suffer catastrophic failure (they suddenly stop working) 
or gradual degradation (reduced optical power for a given input power 
level). [. . .] However, if the laser's efficiency is reduced, more DC 
power must be supplied, more heat is generated, and the likelihood of 
failure increases." said HTTPS://WWW.CDRFAQ.org/faq05.html#S5-27

E.g. Mike Swaine recommends to back up frequently, but backing up 
frequently can destroy a backing-up LASER!

I used to use the same LASER to record (more than) the discs like which 
are reported by this table. Almost each of these discs is almost full 
(e.g. almost 702 MB for a normal CD and almost 4.7 GB for a normal singly 
layered DVD.

[HTML table . . .]
I never detect a problem with a disc from this drive.

"Subject: [5-2] How long do CD recorders last?
(1998/04/06)
The MTBF (Mean Time Between Failures) on these drives is typically 50,000 
to 100,000 hours, and they come with a 1 year warranty. Compare that to 
hard drives rated at between 500,000 and 1,000,000 hours with a 3 or 5 
year warranty and that should give you some idea.

Most of the drives available today weren't meant for mass production of 
CD-Rs. [. . .]

Incidentally, MTBF is not an estimate of how long the drive will last. 
Rather, it's an estimate of the failure rate of the drives during the 
expected lifetime of the device. Once you exceed the expected lifetime, 
which is often on the order of a couple of years, the anticipated failure 
rate increases. If you have new drives with an MTBF of 25,000 hours, and 
you run 1000 units for 100 hours, you can expect to see four of them 
fail. It does NOT mean you can expect them to run for 2.8 years and then 
all fail at once." said HTTPS://WWW.CDRFAQ.org/faq05.html#S5-2
"
says
HTTPS://Gloucester.Insomnia247.NL/media/media.HTML
by me. If I made a mistake, then please consider warning me!

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DVDs are worse than CDs Nioclás Pól Caileán de Ghloucester <Spamassassin@irrt.De> - 2025-11-08 17:44 +0100
  Re: DVDs are worse than CDs ant@zimage.comANT (Ant) - 2025-11-09 02:18 +0000
    Re: DVDs are worse than CDs Nioclás Pól Caileán de Ghloucester <Spamassassin@irrt.De> - 2025-11-09 13:41 +0100
      Re: DVDs are worse than CDs ant@zimage.comANT (Ant) - 2025-11-10 01:16 +0000
        Re: DVDs are worse than CDs Nioclás Pól Caileán de Ghloucester <Spamassassin@irrt.De> - 2025-11-10 02:33 +0100
    Re: DVDs are worse than CDs Nioclás Pól Caileán de Ghloucester <thanks-to@Taf.com> - 2026-01-08 13:54 +0100
  Re: DVDs are worse than CDs Nioclás Pól Caileán de Ghloucester <thanks-to@Taf.com> - 2026-01-09 23:48 +0100

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