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Topic: What is the ACTUAL capacity of a DVD+/-R disc? (Read 7451 times) previous topic - next topic
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What is the ACTUAL capacity of a DVD+/-R disc?

Does anyone here know the actual capacity of a DVD+/-R disc? In a few days I'll have a chance to borrow my father-in-law's DVD recorder for data backup, so I am trying to prepare a few ISOs... but I quickly realized that if I assume the wrong capacity, I'll either waste space or build images too large for the discs.

  The reason I am unsure is that hardware manufacturers are notorious for using different definitions of "Gigabyte" than software manufacturers. So which of the following does a 4.7 GB disc actually store?

a) 4,700,000,000 bytes = 4482.269 Mb = 4.377 GB
b) 4,928,307,200 bytes = 4700 Mb = 4.589 GB
c) 5,046,586,572 bytes = 4812.8 Mb = 4.7 GB

    - M.

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #2 –
Why do you even ask?  Of course the lowest.

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b)



edit: Oh, edited it away, eh? Believe me, it's a). 

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #5 –
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Are you sure? I read somewhere that it is 4700 MB.

Yes, and i know where. On the package of DVD media.

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #6 –
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Are you sure? I read somewhere that it is 4700 MB.

Yes, and i know where. On the package of DVD media.

Pretty confusing stuff.

Oh, by the way, I edited my post at the same time you posted. I guess our actions were concomitant.

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #7 –
I do a lot of Dual Layer DVD -> DVD-R conversion.

I know for sure that DVD-R capacity is about ~4.38GB

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #8 –
Thanks guys... hopefully this will save me a few headaches!

    - M.

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #9 –
4.7·10^9 Bytes, that is ... just the same counting method with HDD
The name was Plex The Ripper, not Jack The Ripper

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #10 –
The way companies calculate storage is beyond lame (not the encoder)...
Someone oughta teach them a lesson.
Wanna buy a monkey?

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #11 –
You can't accuse them of lying

BTW, (1,024)^3 bytes are called a GiB (Gibibyte, not 'GB', Gigabyte, which is 1,000,000,000 bytes). There are also kibi and Mebi, replacing kilo and Mega...

These are the correct terms... and the correct terms are clearly not often used

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #12 –
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You can't accuse them of lying

BTW, (1,024)^3 bytes are called a GiB (Gibibyte, not 'GB', Gigabyte, which is 1,000,000,000 bytes). There are also kibi and Mebi, replacing kilo and Mega...

These are the correct terms... and the correct terms are clearly not often used

ok smartass what is a "nibble" and a "gobble" while we are doing our "words", "bits", and "bytes"? 

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #13 –
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BTW, (1,024)^3 bytes are called a GiB (Gibibyte, not 'GB', Gigabyte, which is 1,000,000,000 bytes). There are also kibi and Mebi, replacing kilo and Mega...

is that a joke? 1024 megabytes s a gigabyte, they rounded to 1000 cause is easier to do math with a base tenth numerin scheme, and cause it looks larger.

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #14 –
Quote
Quote
You can't accuse them of lying

BTW, (1,024)^3 bytes are called a GiB (Gibibyte, not 'GB', Gigabyte, which is 1,000,000,000 bytes). There are also kibi and Mebi, replacing kilo and Mega...

These are the correct terms... and the correct terms are clearly not often used

ok smartass what is a "nibble" and a "gobble" while we are doing our "words", "bits", and "bytes"? 

no one into my competition, free smiley to the winner!

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #15 –
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is that a joke? 1024 megabytes s a gigabyte, they rounded to 1000 cause is easier to do math with a base tenth numerin scheme, and cause it looks larger.

Ehm ISO Gigabyte is 1000 Megabytes!

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #16 –
Quote
Quote
BTW, (1,024)^3 bytes are called a GiB (Gibibyte, not 'GB', Gigabyte, which is 1,000,000,000 bytes). There are also kibi and Mebi, replacing kilo and Mega...

is that a joke? 1024 megabytes s a gigabyte, they rounded to 1000 cause is easier to do math with a base tenth numerin scheme, and cause it looks larger.

@kwanbis: it's not a joke, take a look here: http://physics.nist.gov/cuu/Units/binary.html

@M: if you want the exact size of a DVD or a CD, discover the number of clusters it has (RecordNow can show you that, i don't know of any other program) and multiply it by 2048 (cluster size of CD and DVD) and you'll have its exact size in bytes
Allegari nihil et allegatum non probare, paria sunt.

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #17 –
The real problem is that two different systems are used.  One system (used for blank CDs, memory, etc.) says 1 GB = 2^30 bytes and 1 MB = 2^20 bytes.  The other system (used for blank DVDs, hard drives, etc.) says 1 GB = 10^9 bytes and 1 MB = 10^6 bytes.  The former system has been around longer, is used as the standard in computer OSes and really should be the one to stick with (since measuring bytes should inherently be a base 2, not base 10, operation).

Unfortunately, I don't see it happening anytime soon.  If it was just consistent that would be a partial victory (blank CDs should really use the same system as blank DVDs!)

What is the ACTUAL capacity of a DVD+/-R disc?

Reply #18 –
Part of the difference between DVD-R and DVD+R is that +R has a ~5-10MB overhead, so +R discs are usually slightly smaller than their -R counterparts. But of course exact capacity varies between manufacturer. All numbers are roughly 4700000000 bytes, that is ~4482MB.


In terms of exact numbers, from what I have sitting on my desk:
  • Memorex 4x DVD-R = 4489MB
  • Maxell 4x DVD+R = 4483MB
  • Verbatim 2x DVD-RW = 4489MB
Filesystem overhead should be similar to a CD - on a test compilation I just made with 18000 files and 1600 folders for a total of 4400MB gives overhead of only 9MB.