What's the capacity of a CD?

[AmigaMance]

Hi.
 I thought it was 650MB, but now i see that i'm able to burn (using MakeCD) and view properly CDs with about 703MB of data each. So, what's the true limit?

 Are there any disadvantages from filling your CD with so much data? Does it make it more prone to scratches or anything?
 I have already found one: I burnt a CD with 700MB's of jpegs and my jpg capable DVD player can't recognize it but my Amiga can. Is there anything else i should know?

[Piru]

Wiki: Overburning

There are also 800MB/90min CD-R's on the market.

[Effy]

Two years ago I saw a brandnew Plextor cdrewriter claiming to write 900 Mb ... was pretty expensive and decided that 700 Mb was enough ...

[AJS]

 :-) Your DVD player might need the .JPG suffix after each picture file whilst on the Amiga, most programs don't require it

CD's can have either 650mb or 700mb I think its down to mainly music files? 650mb = 74 minutes 700mb = 80 minutes

[Vincent]

650mb CD is an older 74 minute audio CD which aren't really used anymore.  Infact I buy quite a lot of CDs and I haven't seen one in possibly 4 years.

703mb CD is 80 minutes that were designed and produced after the 74 minute ones had been around for a while.

Check here.

[AmigaMance]

Ok, thanks everyone!
 According to Piru's link, i should not fall into any problems. Perhaps i should handle the cds more carefully as

Many disc manufacturers extend a recordable disc to leave a small margin of extra groove at the outer edge.

 and i, like most ppl grab them from the outer edge.


@Effy
 That extra 200MB sounds appealing!


@AJS
 No, it has to do with the size of the CD. It will recognize it if it's 650MB or less.


@Vincent
 Yes. I see now where this 730MB comes from.

[Lonewolf10]

The CD-R's I use (Maxell CD-R, 700MB, 80 Mins) have a "safe" limit of 700MB. I use Nero to burn CD's (for PC's, haven't tried burning any for my CD32 yet) and if I use overburn (burning beyond the "safe" point) I can add a few MB's of data to the recommended storage level. This can be dangerous to both the CD and the drive, and any data overburned is said to be much less reliable than the "safe" limit.

As far as Amiga's go (unless you are using Amiga One, or Pegasos?) 700MB's is more than enough space for storing files


Regards,
Lonewolf10

[pVC]

Lonewolf10:

mp3 etc are as big on Amiga as on other platforms too

[AmigaMance]

Many disc manufacturers extend a recordable disc to leave a small margin of extra groove at the outer edge.

 My signature says that i'm using a classic Amiga but i don't see how's this make the 700MB more sufficient for me. :-P

[Tomas]

700MB is the official limit, though with most brands you can overburn with at least a few megs or more.
You can also fit a vcd/svcd movie of 800meg onto a 700meg cd to make it more confusing..

[Effy]

A quick search on Google tells me something about :

GigaRec™ allows high capacity storage of up to 900 MB on a 700 MB CD-R disc. With this advanced feature, you can increase the maximum writing capacity up to 30%.*

or worse :

http://pcworld.about.com/news/Apr152003id110273.htm

New PlexWriter Premium CD-R/RW fits 1GB of data onto a standard disc.

Melissa J. Perenson, PCWorld.com

When CD-RW drive speeds reached 52X, the race cooled--until now. Plextor's PlexWriter Premium CD-R/RW drive, released this week, offers the first promising innovations seen in a while.

In addition to hitting maximum write speeds of 52X for CD-R and 32X for CD-RW, the $129 internal IDE drive offers four features that make it stand out in an otherwise-crowded market: 1GB disc capacity, security, quiet operation, and diagnostics.
CD-RW on Steroids

Unlike ordinary CD-RW drives that can fit up to 700MB on a standard disc, the PlexWriter Premium packs up to 1GB of data on a CD. This is achieved using Plextor's GigaRec feature, which "uses a brute-force approach to push more data into the same space" on a disc, says Howard Wing, Plextor's vice president of sales and marketing.

This technology differs from previously announced schemes for cramming more data on a CD, namely Sony's Double Density discs and Calimetrics' MultiLevel technology. Neither format got off the ground, in part because each required proprietary media in order to achieve the higher capacities. Furthermore, those discs were not backward-compatible with other drives.

"There's an important distinction between this and the MultiLevel technology," says Wolfgang Schlichting, research director of removable storage at IDC. "There's no additional hardware cost or media cost involved. If there's no additional hardware or media required, I think users will be interested in using it."

Instead of reinventing the wheel, Plextor is controlling the drive's laser to burn deeper pits of data onto an ordinary CD.

"We had such a satisfactory margin in how we burn a disc using the drive that we were able to increase the bit density from 20 to 40 percent above the standard CD disc. That yields roughly a gigabyte of storage on a 700MB disc," Wing says.
Setting a Standard?

Of course, doing so violates the Orange Book specification, the standard that defines rewritable CDs, first announced in 1990.

[Vincent]

Effy wrote:
Of course, doing so violates the Orange Book specification, the standard that defines rewritable CDs, first announced in 1990.

Yes, but the Compact Disc standard is already being ignored in the DualDiscs that are coming out now so going against already defined standards are nothing new.

Still, interesting reading Effy.

[Zac67]

Since the CD was originally designed for audio, its REAL capacity is 74min x 60secs x 2bytes/sample x 2channels x 44100 Hz = 783,216,000 bytes.

So where's the rest? ISO9660 uses 2048 bytes/sector for data instead of the native 2352 bytes/frame (1 frame = 1/75sec) plus 304 bytes for additional redundancy. This yields 681,984,000 bytes for a 74min CD and 737,280,000 bytes for 80min.

If you're burning an audio CD, VCD or SVCD you will actually be able to use that capacity (CDXA).



If you need more capacity, just use DVD+/-Rs. CD blanks with >80 mins can raise weird problems (e.g. try to skip to the last track on a 99min audio CD) because the standard has no way to handle those sizes.

[Ross1]

Don't forget that CDR/DVDR discs have a relatively short shelf life particularly the cheep ones. The plastic used in the manufacturing process starts to break down after two or three years. This is also dependent of how they are stored and what sort of humidity and temperature they are used in.