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Off-Topic Discussion => General Discussion => Topic started by: Fineus on May 14, 2006, 06:04:10 am

Title: CD Degradation Times
Post by: Fineus on May 14, 2006, 06:04:10 am
As I shoot more and more digital photos, I notice my hard drive filling at an alarming rate with images I won't necessarily want  to access again.

Then it occured to me that although each folder of images could be in excess of 300MB, I could easily back them up onto CD. But what about the life-time of CDs?

My point being that - if I want to come back to them in 10 years time (unlikely, but you never know) - will I be able to use them? I've heard stories that the lifetime of a CD is pretty poor or that it's good as long as you take care of it. I need them to last as long as possible.

Anyone have any input on this?
Title: Re: CD Degradation Times
Post by: Fury on May 14, 2006, 06:07:45 am
http://en.wikipedia.org/wiki/CD-R
Quote
At present, stated CD-R lifetimes are only estimates based on accelerated aging tests as the technology has not been in existence long enough to verify the upper range. With proper care it is thought that CD-Rs should be readable one thousand times or more and have a shelf life of several hundred years. Unfortunately, some common practices can reduce shelf life to only one or two years. Therefore, it is important to handle and store CD-Rs properly if you wish to read them more than a year or so later.
Many of my CD-R's are unreadable after being dumped to shelves for several years.
Title: Re: CD Degradation Times
Post by: Fineus on May 14, 2006, 07:51:51 am
Cheers mate.. but does that mean that yours degraded because you didn't care for them properly - or that they degraded anyway?

I could buy a 200GB external USB hard drive or something and use  that instead... presumably the lifetime of one of those is pretty damn long. But CDs are obviously a little more user friendly.
Title: Re: CD Degradation Times
Post by: Fury on May 14, 2006, 08:40:09 am
The CD's have been laying in my shelves, unused. Don't trust recordable CD and DVD media lifetimes anyway if you really want to read these discs even after 10 years. External hard drives are more durable, but since these are mechanical devices, hard drives are more prone to failures than USB-memorysticks for example. I think external USB/Firewire hard drives are more user friendly than CD or DVD medias, you can fit a lot more data on small physical space, takes a lot less shelf space. Use of external hard drives is pretty easy too, since most PC'-cases have USB-ports on front. In the end, external hard drive can be even cheaper than buying enough CD-R's to fit as much data.
Title: Re: CD Degradation Times
Post by: Fineus on May 14, 2006, 09:03:52 am
I'm inclined to agree. I've never really considered them as a storage medium before but having done some research I've found a very nice 300GB USB2.0 Firewire etc. external HD for around £120. That should be more than enough storage space for the time being.

Provided of course that it doesn't fail etc.

USB sticks etc. are good for small amounts of data but I've yet to see something viable that can back up a lot (100+GB) of data.
Title: Re: CD Degradation Times
Post by: aldo_14 on May 14, 2006, 10:17:49 am
As I shoot more and more digital photos, I notice my hard drive filling at an alarming rate with images I won't necessarily want  to access again.

Then it occured to me that although each folder of images could be in excess of 300MB, I could easily back them up onto CD. But what about the life-time of CDs?

Once the RIAA gets their way, about 12 seconds.
Title: Re: CD Degradation Times
Post by: Shade on May 14, 2006, 10:21:50 am
A USB drive is a good bet for sure. Main wear on most HDs occurs when they are spinning up (as the read/write heads are dragging on the plates until they spin fast enough to create an air cushion), so if you just use it a couple of times a month for backups, it'll last damn near forever as long as you don't stuff it in the freezer, boil it in salt water or use or as a basketball.
Title: Re: CD Degradation Times
Post by: Skippy on May 14, 2006, 10:36:26 am
I suggest writing CDs or DVDs at minimum speed, raises lifetime ;)
Title: Re: CD Degradation Times
Post by: Prophet on May 14, 2006, 11:59:22 am
I suggest writing CDs or DVDs at minimum speed, raises lifetime ;)
Haven heard that one before. :nervous:
Please, entertain me by telling more...
Title: Re: CD Degradation Times
Post by: Cyker on May 14, 2006, 12:20:49 pm
For long-term bulk archival storage, you can't beat a Hard Disk.

DVD's are pretty crap for long-term archival storage
CD's can be okay depending on the dye - Cyanine discs (Deeper purple/blue) are rubbish; 5 years and it'll be totally unreadable.
The best is usually PhthaloCyanine (Light green/gold) - These often have higher error rates and don't burn as cleanly, but the dye is much more stable and is rated at 100 years (BS, but the real figure is likely still much higher than Cyanine).

DVDs degrade much nastier than CD's, presumably because of the track sizes.

You can keep them going for quite a while if you put them in a cool dry dark place 'tho. Warmth is the most dangerous thing to CD/DVD media as it accelerates the breakdown of the dye.
Storing a CD/DVD in direct sunlight will probably kill it pretty quick.


Hard disks OTOH last for ages as long as you don't do anything stupid. If you only plug it in occasionally then it will probably out-live you! ;)
And you can pick up a server-grade 300GB ATA hard disk for like, £50 these days!
(Just don't look at SCSI... a 300GB SCSI hard disk would be more like £600 :eek: )

The ultimate long term storage would be some sort of MO (Magneto Optical) drive, but good luck finding one with any decent capacity these days!


Oh, and re. the thing about burning CDs slower - This is actually false, and can actually make the disc worse depending on the CD burner!
A lot of burners have an optimum speed - Usually 32-40x - If you burn above or below this, discs can actually have MORE errors!

On well made drives, you don't get such a difference 'tho, and in such cases slower speeds can give lower errors.
Title: Re: CD Degradation Times
Post by: Skippy on May 14, 2006, 12:25:23 pm
I suggest writing CDs or DVDs at minimum speed, raises lifetime ;)
Haven heard that one before. :nervous:
Please, entertain me by telling more...

Well, I think my sentence was incorrect  :o
Title: Re: CD Degradation Times
Post by: Fineus on May 14, 2006, 01:57:35 pm
Cheers guys! Right now it really does look like an external HD is the best way for me to go. As I say I only really want it for long-term backup purposes and won't exactly be mis-treating it though I may plug/unplug it frequently depending on what needs backing up.
Title: Re: CD Degradation Times
Post by: Turambar on May 14, 2006, 02:28:29 pm
my FS2 CD's still work...
Title: Re: CD Degradation Times
Post by: Ferret on May 14, 2006, 02:31:14 pm
My Day Of The Tentacle CD still works.

[edit]

Also 7th Guest.
Title: Re: CD Degradation Times
Post by: Fineus on May 14, 2006, 03:13:42 pm
But were they burnt, and if so how long ago?

I imagine there's a clear difference between professionally produced CDs and home-burnt ones.
Title: Re: CD Degradation Times
Post by: Col. Fishguts on May 14, 2006, 03:35:48 pm
I guess they're talking about home-burnt CDs. Professionally produced (pressed) CDs have a much longer lifetime.

As far as reliable long-term mass storage goes, most professionals advise not to use CD-Rs ors DVD-Rs. But personally I haven't experienced many CD-Rs failing on me. My oldest home-burnt CDs are from 1997 and are still working fine.
Title: Re: CD Degradation Times
Post by: SadisticSid on May 14, 2006, 04:01:09 pm
I switched on an old 8086 IBM XT a few months ago. The 10MB hard drive span up - although emitting an awful noise in the process - and everything seemed to work still, DOS 3 booted up fine. Not bad for >20 year old technology.
Title: Re: CD Degradation Times
Post by: Cyker on May 14, 2006, 05:28:03 pm
Yeah, I have a friend with an Amiga 500+ that likes to boast that his 20MB SCSI hard disk still works too :P

And yeah, burned CDs and stamped CDs are a whole different kettle of fish.

Assuming you take care of it and it's made properly, a stamped CD will probably last centuries!
Title: Re: CD Degradation Times
Post by: BlackDove on May 14, 2006, 05:31:56 pm
My FS2 CD's from 98/99 still work and I have been abusing them substantially.
Title: Re: CD Degradation Times
Post by: Nix on May 15, 2006, 02:24:08 am
I made copies of my FS1 CD's when the game came out and they work great.  One big thing I've noticed, is the particular type of media used.  I myself use the metal AZO-based media that Verbatim makes, a darker dye than the el-cheapo Imation/TDK/Samsung discs.  Basically, anything made by CMC Magnetics is crap.  The Verbatim media is made by Mitsubishi Chemical, and I've used those discs religiously for the past 3-4 years when my old Ricoh drive wouldn't burn to anything BUT AZO dye media.  I do estimate that these discs will eventually degrade, as the older CMC discs I've got have degraded and stopped working, but anything using the darker AZO dye has lasted longer and hasn't quit since 1997-ish for me.  Just something to consider, don't go buying the cheap, bulk media you can get for pennies (ridata, etc) spend a bit extra for your media if you plan on using it for archival purposes.  The Ridata media is great if you're making quick copies, disposable stuff, or sharing work-related files (wink wink) with your friends.
Title: Re: CD Degradation Times
Post by: Ulala on May 15, 2006, 12:27:51 pm
Oh, and re. the thing about burning CDs slower - This is actually false, and can actually make the disc worse depending on the CD burner!
A lot of burners have an optimum speed - Usually 32-40x - If you burn above or below this, discs can actually have MORE errors!

When I burn data DVDs for work and run the "verification" process or whatever after to make sure it's error free (supposedly), if I burn at 8x speed, the DVD gets racked full of errors. 4x speed though, and it's fine. I don't much care for dealing with burnable media.  :sigh: