# How did someone fit 740MB on a 700MB CD-R? **URL:** \ **Category:** Factual Questions\ **Created:** [April 7, 2004, 1:18pm UTC](https://boards.straightdope.com/t/how-did-someone-fit-740mb-on-a-700mb-cd-r/238730 "2004-04-07T13:18:16Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Spiff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiff/32/9852_2.png) [@Spiff](https://boards.straightdope.com/u/Spiff)\ **Post date:** [April 7, 2004, 1:18pm UTC](https://boards.straightdope.com/t/how-did-someone-fit-740mb-on-a-700mb-cd-r/238730/1 "2004-04-07T13:18:16Z")
I’ve come across a situation that is making me scratch my head and say, “Huh?” I’ve got an 80-minute, 700MB CD-R filled to the brim (and more, as you’ll see) with music. (The disc came from a friend who’s in the band that created the music, so it’s legit). Now, when I’ve tried to make a copy of this CD-R, I cannot fit the whole thing onto another 80-minute, 700MB CD-R disc. Why not? Well, it’s because after I import (extract, rip) the files to my computer, it turns out that the sum of the audio files exceed 700MB … 740.5MB to be exact. Why is this? How did the band burn a 700MB-capacity CD-R with 740.5MB of audio files? (I can’t ask them, 'cause they’re on a tour right now.) I’ve extracted the files in both AIFF and WAV format, and I get the same exact file sizes. When I check the properties of the original CD-R as it sits in my computer drive, my computer comes back with that same number: 740.5MB of data on a 700MB disc! For the record, I used iTunes on a Mac to import the files. Strangely enough, iTunes did perform a burn of a 700MB CD-R, but the 23rd and final track (a 2:10 song) track was cut off after five seconds. I’m surprised that iTunes would attempt to burn a CD-R, “knowing” that I was attempting to record files that exceeded the capacity of the disc. (I would have at least expected a warning!) BTW, the total duration of the songs is 72 minutes … eight minutes under the 80 minute limit of the CD-R. Can anyone figure out what’s going on? ---
**Author:** ![jmizzou](https://avatars.discourse-cdn.com/v4/letter/j/edb3f5/32.png) [@jmizzou](https://boards.straightdope.com/u/jmizzou)\ **Post date:** [April 7, 2004, 1:29pm UTC](https://boards.straightdope.com/t/how-did-someone-fit-740mb-on-a-700mb-cd-r/238730/2 "2004-04-07T13:29:12Z")
They may be [overburning](http://www.techtv.com/screensavers/answerstips/story/0,24330,2351686,00.html) the disk by writing on the part of the CD that is normally left blank. It’s a bit risky (the disk or the writer could be damaged), and the CD won’t always work with all audio players, but it is occasionally useful. ---
**Author:** ![billy\_meade](https://avatars.discourse-cdn.com/v4/letter/b/43a26b/32.png) [@billy\_meade](https://boards.straightdope.com/u/billy_meade)\ **Post date:** [April 7, 2004, 1:48pm UTC](https://boards.straightdope.com/t/how-did-someone-fit-740mb-on-a-700mb-cd-r/238730/3 "2004-04-07T13:48:20Z")
This is from the CD-R Faq: "Incidentally, don’t get confused when you discover you have 700MB of audio extracted from a CD that only holds 650MB. Audio sectors use 2352 bytes per sector, while standard CD-ROM data uses 2048 (the rest is for error correction). You can put roughly 747MB of audio onto a disc that only holds 650MB of data. " [http://www.cdrfaq.org/faq03.html#S3-8](http://www.cdrfaq.org/faq03.html#S3-8) So that might explain it ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [April 7, 2004, 1:55pm UTC](https://boards.straightdope.com/t/how-did-someone-fit-740mb-on-a-700mb-cd-r/238730/4 "2004-04-07T13:55:06Z")
I found this when I asked a Teradata consultant I know to burn a copy of a demo CD as he had done for previous versions. He found he couldn’t but fortunately I was able to order one from the factory. Unfortunately one I can’t make a backup copy of. ---
**Author:** ![Spiff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiff/32/9852_2.png) [@Spiff](https://boards.straightdope.com/u/Spiff)\ **Post date:** [April 7, 2004, 5:58pm UTC](https://boards.straightdope.com/t/how-did-someone-fit-740mb-on-a-700mb-cd-r/238730/5 "2004-04-07T17:58:49Z")
Thanks for the replies, everyone. So, does anyone know if iTunes can be used to overburn CD-Rs? ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [April 7, 2004, 8:27pm UTC](https://boards.straightdope.com/t/how-did-someone-fit-740mb-on-a-700mb-cd-r/238730/6 "2004-04-07T20:27:45Z")
- - - Well the quickest way to find out is just go crazy and try overburning a disk and see what happens. How far you can overburn depends on what hardware, software and media you are using. … Subject: [3-8-3] How can I exceed the stated disc capacity (“overburning”)? --\> [http://www.cdrfaq.org/faq03.html#S3-8-3](http://www.cdrfaq.org/faq03.html#S3-8-3) * * * - There are some very low-level “open-source/_format_-hacker-style” programs out there for forcing CD-R drives to do strange things to CD-R’s, but I dunno how many are available for Mac… ~ ---
**Author:** ![Ludicrous](https://avatars.discourse-cdn.com/v4/letter/l/82dd89/32.png) [@Ludicrous](https://boards.straightdope.com/u/Ludicrous)\ **Post date:** [April 7, 2004, 8:51pm UTC](https://boards.straightdope.com/t/how-did-someone-fit-740mb-on-a-700mb-cd-r/238730/7 "2004-04-07T20:51:34Z")
**Spiff** , itunes can’t. Actually itunes and Mac OS X’s built-in burning functions actually seems to allow less burning space than other programs. Roxio or other 3-rd party softwares should do the trick.