How reliable is CD-RW really??

[KennyR]

I used to think 100% reliable - what I put on the disc, I got back off byte for byte. But lately that confidence has been damaged.

I was burning a CD-RW with a large (637MB) linux image for a Mandrake install with MakeCD, but mandrake was failing to install, complaining that the image on the CD failed a checksum. I checked it manually, and sure enough, it did. So I reburnt it.

I've burned this same image on several different CD-RW of different brands on at least two different drives, and always the file fails its checksum. Doing a direct compare to the file I still have on HD, often more than 310,000 bytes are wrong - about 0.06% of the full image. There are single byte errors and even whole areas of the file filled with 0 or by repeating bytes like 0x59595959...

It's not the drive or the computer or MakeCD, because I get the same problem on my family PC's burner. The original file I downloaded is fine and unpacks. If it's the discs then I have two bad brands with a full load of defectives. Whatever I do I can't get this file to write properly on a CD-RW.

Does anyone else get this? 0.06% might fall within some kind of quality control, but i need 0.0% error. Are CD-RW discs really so unreliable?

[adolescent]

In a word, no.  I've never had any problem with CD-RW disks.  I'd suspect the drive or the authoring software  first but since you said you tested it on another computer I'm at a loss.  

[jdiffend]

I've owned several CD-R or CR-R/W burners since 1994 and have burned several hundred disks and here's what I've observed (many of which have nothing to do with your problem):

1. If there is a problem in the source file the software doesn't always detect it and you will always get a corrupt disk.
2. Not all CD burners are created equal.  I rarely ever have problems... my friend has nothing but problems.
3. I started getting errors on disks right before a CD burner died.
4. Some CD-R or CD-RW brands stink... they are best used as coasters.  
5. CD-RW disks seem to be more sensitive to scratches and dust.
6. Multi-session disks have a lot more problems.  (probably driver support issues)
7. Some things just don't seem to work on CD-RW disks... you have to use a CD-R.  

[DonnyEMU]

I haven't had a failure since 96-97 myself.. Sometimes the coating on the disks also makes a big difference. I always make sure the CD I am buying matches rating of the burn speed of the drive. Some of the earlier coatings had problems with some lasers reading.. I have one cd that's totally unreadable with my current drives but works just fine with my old one..

[JimS]

I've burned a lot of CDs over  the last few years. Because my pc isn't anywhere near state of the art, I've always 'premastered' my CD burns to a disk file first. Then burn 3 copies to be safe. :-)
I've been worried about this recent concern over the long-term stability of the CDR media.  Especially with all my Amiga magazines now burned to CD & the paper versions recycled....  I've been considering one of those cheap 120gig HD's as backup for my CDs. :-)

[KennyR]

I know the perils of crappy discs. I got 10 Memorex cdrw and they weren't even detected on my drive - I had to format them on my family computer at least once first to get them to be recognised. Then some of them wouldn't re-format at all, and are just dead coasters. I paid a lot of money for that crap. Grr! :pissed:

But a second pack of Samsung seemed to work a treat, with no problems whatsoever. I've been using them for backup and VCD. But with the worry about the integrity of the data on them, I may go to restore a backup one day and end up with trashed files. :-x

Oh well, at least cdr has always been faithful. Oh, and by the way, it's only really crap cdr that don't last very long. I have it on good authority that normal ones are still working after 5 years or more...

[csirac_]

I work at a PC sales/repair shop during holidays. From what I've seen, CDRWs are usually not worth it for the general public.

If you are downloading ISOs, especially for Linux distros, there is almost always an MD5sum file for each ISO. It's a cryptographic checksum that can usually tell if your ISO is corrupted at your end (the MD5sum is only a few KiB).

I've seen more than one business use CDRWs for daily backups. The person doing the backups just leaves the CDRW sitting on top of the PC, not in it's case, and after a while when they do need to recover data the CDRW is useless.

I read somewhere that CDRWs have only 40% reflectivity of a pressed CDROM (CD-Rs were something like 70%). So scratches, dust, fingerprints affect them more. And if you are adding to a CD using multisession or even worse - UDF packet writing software, the file system/TOC area becomes more complex - small errors in these places could confuse a computer easily.

So unless you're testing an AROS or a KNOPPIX distro regularly, I wouldn't bother :-)

I hope AmigaOS4 will support USB Flash drives...

- Paul

[nac]

I have been burning discs for about 4 years now and I have learnt 2 things.

1. Stay away from Yamaha burners. Seem to be very fussy about what they will and wont write to. Although I think Yamaha dont make any drives any more.

2. Stay away from Marlen ( or Marlin - the font makes it hard to read ) discs. I bought a pack of 10 and I have just binned most of them as they became either unwritable or forgetful.

[jdiffend]

I've been worried about this recent concern over the long-term stability of the CDR media

I wouldn't worry too much.  I burned a few audio CD's back in 95.  They have been carried around in my car for years and they still work fine.

If it really worries you, buy a different brand than the ones you already used and burn a 2nd copy.  One of the two should survive over 5 years even if one brand is bad.  

If you have some non-copyrighted stuff that other people would be interested in you could share it on a peer to peer file sharing service.  Someone would be bound to have a copy if you ever needed it.

[Tomas]

I have not had such a prob either... Cant it be the software?? I know that for example nero has problems with certain images, ends up with errors on the cd.

[Gerbinist]

I got a couple of tips for you:

- try to burn the image on a very low speed, say 2. I got this problem with vcd's that at the end had a lot of distortion. With setting the speed to 2 this is gone

- read what speed your drive supports and what the media supports. You said something about unable to format. This can occur when trying to burn a cd that is for 1-10 speed rw. Your writer can be the one that doesn't support this. I got a Plextor which only let me use "Multispeed" cdrw's which are 1-4.

Hope this helps,

Gerb

[amigamad]

I have once made a backup of the pc game max payne that worked ok .But i only use cdrw disc for small files now and i use infiniti 80 min 10 speed cdrw i have had no problems with these discs at all.Sometimes burning at a slower speed works better.

What make writer do you use as i have seen a few samsung drives that cant even read discs properly. :-)

[iamaboringperson]

How reliable is CD-RW really??

I don't think they are very reliable. :-(

That's why I use .... ZIP!! :-)

[DoomMaster]

To KennyR:

I personally have had problems with CD-RW disks, so I do not use them.  Try burning the file to a CD-R disk using the ISSI 9660 format.  Make sure that you finalize (close) the CD.  This should work.  [color=FF0000]I never do a multi-session burn.  A multi-session CD-R is just too unreliable.[/color]  KennyR, I hope that I have helped you.     :-P

[KennyR]

So the basic consensus of opinion is: "CD-RW are crap, don't use them"?

I hear this a lot, and I'm starting to think that way myself, despite their advantages. Does anyone have anything to say that's more flattering to CD-RW, or are they really crap?

@Gerbinist

No, I'm afraid burning at lower speeds didn't help. It may be the reading of the cdrw that's going wrong, not the writing.