Not enough disk space on DVD-RW

temhawk wrote:
Hello, I bought some DVD-RWs and the package says that they have 4,7 GB capacity. However, when I calculate the available space in Finder, it's much less than that (about ~4,3 GB).

Why is that, and can I somehow get all of the 4,7 GB available? The files I wanted to burn onto it are ~4,4 GB in total.

4.3 GB is about right. Check here:
http://club.cdfreaks.com/f33/actual-size-dvd-r-4-7gb-139256/
Some DVD writers can squeeze a bit more onto the DVD but once you start working in the margins you are moving into coasterville 🙂
If you are writing a movie or photo DVD, Toast and other apps will compress your files to fit, naturally with a small loss in quality.
Raw data files cannot be compressed while recording. But they can be compressed first.

Message was edited by: nerowolfe

Not really. This is the way all disk capacities are advertised. You always have to factor in space for formatting info, plus the "1000 vs 1024 conundrum."

Probably because both are correct but one sounds like you get more for your money.
If you walked into a shop and was confronted with both at the same price you'd probably buy the 4.7s right?

temhawk wrote:
Thank you 🙂

Then why does it say 4,7 GB? Why isn't there the space that it's supposed to have? Sounds like a rip-off, literally.

It's not a rip-off as much as an advertising gimmick. We see it all the time in the advertising world.
When you buy a 500 GB HardDrive, are you aware that that number is based on a 1000 "K as opposed to the actual 1024 "K"? For GB, the factor is 1.073. So divide the 4.7 GB by 1.073 and lo! and behold, you get 4.38 GB. In general the rule is "caveat emptor."
When I insert a blank DVD into my MBP and run Toast, I get the honest size of the blank DVD, 4.38 GB. Ignore the 4.7 number.

From wiki (not generally a reliable source unless taken with many grains of salt)

"As with hard disk drives, in the DVD realm gigabyte and the symbol GB are usually used in the SI sense, i.e. 109 (or 1,000,000,000) bytes. For distinction, gibibyte with symbol GiB is used, i.e. 230 (or 1,073,741,824) bytes. Most computer operating systems display file sizes in gibibytes, mebibytes and kibibytes labeled as gigabyte, megabyte and kilobyte respectively.
Each DVD sector contains 2418 bytes of data, 2048 bytes of which are user data.

Size comparison: A 12 cm DVD+RW and a 19 cm pencil.
There is a small difference in storage space between ‘+’ and ‘-’ formats:
Capacity differences of writable DVD formats
Type Sectors Bytes GB GiB
DVD−R SL 2,298,496 4,707,319,808 4.71 4.384
DVD+R SL 2,295,104 4,700,372,992 4.70 4.378
DVD−R DL 4,171,712 8,543,666,176 8.54 7.957
DVD+R DL 4,173,824 8,547,991,552 8.55 7.961

http://en.wikipedia.org/wiki/DVD#DVD_capacity

temhawk wrote:
Okay. I didn't think that a DVD disk would need formatting information. I've always thought of it as a plain old carrier device that you just throw information on to.

Well thanks guys!

Back in the more honest days 🙂 floppies were labeled 1.44 MB, which was the actual formatted capacity. The actual disks were closer to 1.7 MB but nobody advertised then as such. Some companies (MS for one) actually found a way to use the full capacity, but again, honesty prevailed back then in the last millennium.

Good point. I don't think they are going to change their minds anytime soon though. It's difficult to get your head around. They are actually using the two systems at the same time, the decimal 4.7 is converted to a binary number and emerges at the other end as 4.38

Yup. It is and it isn't. If you know what I mean. 4.7 Decimal GB is 4.38 Binary GB.
I always like to think of a CD as using i wide laser and DVDs as a narrow one. So you'd get more revolutions on the DVD surface. Like when you buy a vinyl LP and some were 33 1/3 rpm and others were 45.
Same physical size and appearance though.

It'd be nice but I think the disc format is different too.

i really need help!
i have the new imac with leopard and i just wanted to burn am movie.
bought a 4.7 GB dvd-rw and in the other hand the movie (information said 4.4 gb). now when i try to burn it on the empty dvd it says ON THIS DISC INSERTED IS NOT ENOUGH SPACE!

i am desperate now because happened a few times!
what did i do wrong or what do i NOT know i have to do first?

thanks
HELP!