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The Reliability of Optical Disks

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Re: The Reliability of Optical Disks

#11

Post by superkuh »

bufferoverflow wrote: post #8

I have many degraded CDs and DVDs from 2000-2010. No drive would read them. Most from reputable brands. Most non-RW. All stored in dark places, indoors.

I have many degraded CDs from 1998-2010. In 2019 almost all of them would read, eventually, even as metal flakes came off the disks. I recovered most data from most. My CD-Rs were a mix of brands, nothing special or expensive. But my CD-drives are old too, from 2006(?) or so. I wonder if like with floppy disks and drives, modern CD drives are less capable than old ones because they're no longer a premium product?

Re: The Reliability of Optical Disks

#12

Post by gotaquestion »

I have 5-1/4" floppies the early 80's that still read fine. I wonder if 3.5" floppies from 1995 would still work. I have a feeling the media was made more robustly in the early 80's because the sensors weren't that precise, so bits were written with way more field than they needed. Maybe in the 90's when so many bits were crammed on to the 3.5" that they weren't written as strong?

Perhaps the same is true of optical media. Are higher density optical disks from later in the era less robust than earlier tech.

Like the way Hobart mixers from the early 1900's are built like tanks and can outlast ones built today to save money.

Re: The Reliability of Optical Disks

#13

Post by blueflow »

ghostly_s wrote: post #3

I'm a bit skeptical of these conclusions without more detail on the methodology. Does "100% success rate!" mean the author was able to mount the disks and read some files off them? Or did they actually have some method to verify check-sums of every file to identify bitrot?

It matches my experience. Even decades-old CD-ROMs only fail when they are scratched or physically damaged, which you can prevent by keeping them in appropriate cases and always put them back after use.

Re: The Reliability of Optical Disks

#14

Post by btrettel »

superkuh wrote: post #11
bufferoverflow wrote: post #8

I have many degraded CDs and DVDs from 2000-2010. No drive would read them. Most from reputable brands. Most non-RW. All stored in dark places, indoors.

I have many degraded CDs from 1998-2010. In 2019 almost all of them would read, eventually, even as metal flakes came off the disks. I recovered most data from most. My CD-Rs were a mix of brands, nothing special or expensive. But my CD-drives are old too, from 2006(?) or so. I wonder if like with floppy disks and drives, modern CD drives are less capable than old ones because they're no longer a premium product?

> I wonder if like with floppy disks and drives, modern CD drives are less capable than old ones because they're no longer a premium product?

When I ripped CDs I had from the 00s in 2019, I used an external Blu-ray drive from probably 2018 or so. Seemed to work okay; see [0]. I didn't have access to anything older so I can't compare but I think both new and old drives are probably good.

[0] https://news.ycombinator.com/item?id=30889474

Re: The Reliability of Optical Disks

#16

Post by causality0 »

Finally, optical disks are more expensive than HDDs - at least in cost per GB. A 4TB NAS branded HDD costs ~AU$160, which is ~4c/GB. My last BluRay purchase was for 3 x 50 spindles of 25GB disks costing AU$330, which works out to be ~9c/GB.

For anybody with deep knowledge of the industry, is the price of discs an accurate reflection of costs or is it inflated by secondary factors such as attempts to make the media more expensive to deter piracy or Sony's desire for high profit margins on data storage? I well remember Sony's shenanigans from the 2000s when they made great hardware and then only accepted MemoryStick instead of SD cards while charging much more for their flash format. I was so excited for BluRay and then prices just never came down enough to be practical.

Re: The Reliability of Optical Disks

#17

Post by otterley »

bufferoverflow wrote: post #8

I have many degraded CDs and DVDs from 2000-2010. No drive would read them. Most from reputable brands. Most non-RW. All stored in dark places, indoors.

The article focuses on Blu-Ray media, which has different physical characteristics than CD-R and DVD.

Re: The Reliability of Optical Disks

#18

Post by rascul »

chrisseaton wrote: post #10
rascul wrote: post #4

It feels weird to me to call optical media disks instead of discs.

It's American English / British English isn't it?

Laser disc, compact disc, digital video disc, and blu-ray disc are (from what I understand) officially spelled with the c. I'm in the US and that is the typical way to spell it that I see, but I also see the k is generally used for hard disk and floppy disk.

That said, there are a lot more instances of "disk" than "disc" used in the comments here so far.

Re: The Reliability of Optical Disks

#19

Post by [deleted] »

blueflow wrote: post #13
ghostly_s wrote: post #3

I'm a bit skeptical of these conclusions without more detail on the methodology. Does "100% success rate!" mean the author was able to mount the disks and read some files off them? Or did they actually have some method to verify check-sums of every file to identify bitrot?

It matches my experience. Even decades-old CD-ROMs only fail when they are scratched or physically damaged, which you can prevent by keeping them in appropriate cases and always put them back after use.

[deleted]

Re: The Reliability of Optical Disks

#20

Post by agumonkey »

bufferoverflow wrote: post #8

I have many degraded CDs and DVDs from 2000-2010. No drive would read them. Most from reputable brands. Most non-RW. All stored in dark places, indoors.

Interesting, I was surprised to be able to read medium or low quality brands from 99 well into 2010s. And I took no precious care.
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