R versus RW - Which Really Lasts Longer?

[indolikaa]

Good Morning!

I have found several sources regarding the method of manufacturer, but little regarding the testing done to answer this question. I would have thought RW because RW is based on a phase-changing crystalline material while R is based on a 'stabilized' organic material.

All things being even, I would expect and inorganic substance (especially a crystal) to hold its composition far longer than something based on an organic mixture of any type. This assumes, of course, that an RW disc is never rewritten from its original phase-change cycle.

Any links or information would be greatly appreciated.

.indolikaa.
Organic Goo

[ronnylov]

But a RW is erasable and if it's erased then it's lost...

[lordsmurf]

Most of my CD-RW and DVD-RW die after a few dozen uses. Especially the cheap ones.

It's a temporary storage medium, never meant for long holding life.

[tompika]

I've got about 50 pieces of DVD+RW discs.

Two of them (from last year: a Philips and a Memorex) have been erased about 120 times and still going strong.

I don't know whether the cheap ones will last that long but I'm not dissapointed...

[lordsmurf]

Also, RW's don't write well once scratched.
Even the tiniest scratches.

[tompika]

Speak for yourself.
The ones I was talking about are full of tiny unavoidable scratches.
I'll post some images as soon as I get home tonite

How is your vacation, lordsmurf?

[lordsmurf]

Speak for yourself.
The ones I was talking about are full of tiny unavoidable scratches.
I'll post some images as soon as I get home tonite

How is your vacation, lordsmurf?

Yeah, I am. I think my RW discs scratch themselves sometimes. I travel with them a lot, easiest method to transfer large work files.

Vacation keeps getting interrupted, find myself online a lot right now. Sucks.

[Kingnog]

Also, RW's don't write well once scratched.
Even the tiniest scratches.

LOL! I have two sony cd-rw's. One is covered in millions of tiny scratches, the other one is covered in the same number of much larger scratches. When doing a scandisk with nero on the disk, it finds that 50% of the disk is 'damaged.' Also, each has been rewritten at LEAST 300 times...probably more (used for a ton of vcd testing).
Even after all this, the disks work perfectly, both in PC and standalone dvd player

[gmatov]

Lordsmurf,

Are you saying that the data is lost aafter X period of time or the disk is unusable after X rewrites?

I think Indoliika's near last statement, assuming the disk is not rewritten from the original... changes the equation.

Just how long will the data last if you write it, say a backup of your sys, store it, and if you crash next month, next year, etc, will it be there?

And, you can't retrieve it on a monthly basis, run a checksum or something, and say, yep, it's still good. Hell,the 3rd or the 19th reading might be the straw that breaks this camel's back.

We're at their mercy, aren't we? It's almost like religion. "They say, we believe, that settles it." (Personally, I don't believe them. They sold us something. A used car dealer does that, and do we believe them?)

Cheers,

George

[lordsmurf]

Like other cases, it'll be as good as the original write. My issue is more and more the "original write" is worse each time. First time 100%, next 90%, then 80%, and so on and so on ... eventually going into my trashcan.

The phase change is not perfect. Dies in time. Much quicker than the "lifetime" given by manufacturers.

Again, this is totally independent of write-once -R and +R discs.

Only applies to phase change media.

And normal wear and tear has it's way with them. The re-cool, re-heat effect AND the scratches AND the dust AND the warping AND the dye deterioration as it floats somewhat to allow for the phase change.

Although most of my CD-RW are still good. Cannot say the same for any -RW, not PVC, not RITEK, none of them.

[tompika]

Unfortunately I couldn't make a shot to show how scratchy they are
- due to the reflective surface - but all of them are perfectly usable (writing/reading)
Oh yeah, and I store them in CD wallets

[gmatov]

Tompika,

Couldn't you just lay them on your scanner? I don't know why everyone has to ddig out the camera.

The scanner is better for this. Even more or less 3 dimensional, "Course if you have a sheet fed multifunction forget it. Hard to feed.

Cheers,

George

[lordsmurf]

Tompika,

Couldn't you just lay them on your scanner? I don't know why everyone has to ddig out the camera.

The scanner is better for this. Even more or less 3 dimensional, "Course if you have a sheet fed multifunction forget it. Hard to feed.

Cheers,

George

My scanner is no competition for a Nikon D1, plus the speeds are better. That's why I dig out a digital camera.

[gmatov]

Well if you have 1200 X 2400, that's near 3 megapixel, but I meant to not get the flash back.

I'll have to scan one to see what it looks like, whether scratches show up.

Hell, even that might be like scanning a light bulb. Don't know.

[indolikaa]

Hello.

George was correct, my reference to RW was under the assumption that the disc would be recorded to once and locked away in the vault. Never to be rewritten again but most certainly to be read again.

I was having an argument with myself regarding which would likely be more stable. Maybe it's just me but I figured crystalline over organic goo any day of the week.

I realize that any long-term storage of CD/DVD media involves proper maintenance, and I do own a pair of CD/DVD rewinders to help ensure those pits and lands don't stretch out too far over time.

.indolikaa.
Lots of Idle Time

[gmatov]

Indolika,

That rewinder is a good idea.

Be a good idea to slow down your read speed, too. If you spin the disk too fast, centrifugal force might spin the spiral all out to the very edge

Talk about data density!!!

[tompika]

The scanned discs as promised.
Unfortunately the scratches do not show up on the pic but they are there.

[tompika]

This is from an other thread but they are similar so why keep two of them running.

So, if we re-write, we are writing to a disk full of pits, and, good for you if there is supposed to be a pit there, but what if there should not be? The burner is not going to "fill in" that pit, make it either reflective or diffusive.

That's pretty much why I full erase. I have the pictures somewhere (from the Phillips website, I think) that show what -RW discs look like under a high-power microscope. The 'burned' areas (actually crystals in their amorphorous state) are not real easy to see against a background of 'non-burned' crystal areas. It just seemed like a safer bet to 'zero-out' the disc before reusing it.

Michael Spath's answer:

Of course it will "fill in" that pit, otherwise direct overwriting
would not be possible at all. While overwriting a DVD+RW,
the laser power is kept at erase level on regions where you
don't want to write marks : this guarantees that the disc will
contain the exact mark/space sequence you want.

Now the +RW specification requires the media to support
1000 DOW cycles, but media quality of course plays a large
role in the actual figure. Can full erase cycles increase
this number or incresae compatibility with picky players ?
In theory it should not, but now I don't know how every
media and player behave, so it could be that in some
special conditions erase cycles can make a difference.

[indolikaa]

This is from an other thread but they are similar so why keep two of them running.

Hey! That thread was regarding erasability issues. This thread is regarding shelf life issues. Erasibility. Shelf-life. One we want to destroy. One we want to preserve. Erase bad. Preserve good.

I just ordered 100 DVD Rewinders for all my friends, and if you want Santa to throw in a free bottle of blinker fluid, you'd better be nice, tompika!

[tompika]

I'll be a good boy, promise....

I'm still a bit confused though:
Why do we drink blinker fluid and preserve badly destroyed shelves

[indolikaa]

I was about to answer your question, but then I saw your avatar...

The answer has slipped my mind.