How can DVD-Rs claim 4.7GB?

[Slaimus]

The actual capacity is 4.38GB. CD-Rs live up to their claimed 650/700MB designation including all overhead data, so how do DVD-Rs get away with that?

 

[kami]

Probably for the same reason hard drive companies get away with calling a 189GB drive a 200GB drive.

 

[fumbduck]

uh, my dvd+rs are 4.7gigs

 

[AkumaX]

4.7gb = 4,700,000,000 bits = 4.37Gbs

 

[Slaimus]

My point is that CD-Rs do not do this, they actually do store 700 real MB.

 

[MustISO]

Originally posted by: fumbduck
uh, my dvd+rs are 4.7gigs

Not sure how that's possible. All DVD recordable are the same size (dual layer excluded) Load one up in DVDDecrypter and let me see it.

 

[sohcrates]

when i try to burn 4.7 gb dvd+r's i can only fit on about 4.4 to 4.5 gb worth of data...but on 700mb cd-r's i can fit 700 mb data

always wondered why

 

[bmacd]

probably for the same reason that a 1.44mb floppy can only be written at 1.38mb

-=bmacd=-

 

[Kelvrick]

Christ, mods moved it in the middle of me replying, gotta type it over now.

Its because 700mb = 700mb. Everytime you hit the 1000 mark of anything, you get the confusion of 1gb=1000mb instead of 1024mb. Same thing with floppies since they're past where kb turns into mb.

 

[EeyoreX]

Its because 700mb = 700mb. Everytime you hit the 1000 mark of anything, you get the confusion of 1gb=1000mb instead of 1024mb. Same thing with floppies since they're past where kb turns into mb.

Which is the same reason that the current "issue" with hard drives has arisen. The "problem" has existed all along. The issue is that no one noticed when hard drives were 800MB. Now that drives are 200GB the difference actually is is more noticable. Same thing here.

\Dan

 

[Slaimus]

But this is an extreme case. At least HDs are honest to the MB level. For DVDs u need to goto the bits level to get the 4.7 (4.7 terabits counting by 1000s). It's only 4.3GB 4,400MB 4,500,000B or 4,700,000,000b (rounding off generously).